Part 4: Mechanical and Chemical Filtration

In this article we are going to discuss filtration. Filtration is broken down into 3 different types; mechanical, chemical and biological. I will be discussing each type in detail. This article will cover mechanical and chemical filtration with biological filtration to be covered in the next article.

To begin, we will cover mechanical filtration. Stated simply, mechanical filtration removes debris or compounds from the pond through a mechanical device. The device could be as simple as a net or as complicated as a foam fractionator. Every mechanical filter has a specific purpose. When looking at mechanical filtration it is important to first identify what you are trying to accomplish and then choose the correct product for the solution.

Most commonly on a pond we see a skimmer; which is a mechanical filter used to remove floating debris from the surface of the pond. Within the skimmer there are usually two different devices. First a weir designed to take water from the surface. Next a net or basket is used to collect debris. When looking at mechanical filters, we need to analyze how well it will do what it is intended to do. Using our skimmer example, let’s break down how it is supposed to work and determine what to look for in a skimmer.

The first thing a skimmer is supposed to do is remove debris from the surface using a weir type device. Water is intended to enter the skimmer by going over the top of the weir that floats so that only a thin layer of water goes over the top. Therefore, any water that enters the skimmer opening by not going over the top is a waste. In this way we can get a good idea of how well it will work by looking at its construction.

Most skimmers use a door that is hinged at the bottom. Yes, water will go over the top as long as the amount of water being pulled in is more than the amount of water going under the door and along the sides of the door. If the skimmer has an 8 inch weir with a ¼ inch gap around the door, the area of the gap would be approximately 5 square inches. That is almost the same amount of area as a 2 inch pipe. This is with the door shut, but as the door opens, the gaps on the sides get larger and less water is drawn from the surface. With the door shut as much as 1000 gph can go around the door before it starts to take water from the surface of the pond.

The second part of the skimmer is the net or basket that catches debris. The first thing to look at is whether the net or basket is going to catch all the debris entering the skimmer or can some of the debris get past without being caught. Also make sure the holes in the net or basket are the correct size to catch the debris you are trying to remove from the pond.

Every pond should have at least one mechanical filter and usually more than one. Not every mechanical filter is easily examined to determine if they will indeed perform the work they are intended to perform. A good example is a foam fractionator or protein skimmer. Their purpose is to remove dissolved organic materials from the water. One problem is that you can’t see these materials so how do you determine if the device is going to work? Even though you can’t see them, you can see the effect they have on the pond water. The dissolved organic materials will cause bubbles on the surface of the pond to take longer before they break. With this knowledge we can determine how well the foam fractionator is working.

Next let’s cover chemical filtration. Chemical filtration is accomplished by adding a chemical to the water to remove some substance from the water or tie it up so that it is no longer harmful. Chemical filtration has a limited use in that once the chemical is used up it no longer has an effect on the water. Chemicals used for this type of filtration can range from dechlor to ozone.

As with any filter you should first determine what you are trying to remove from the water. You then select a chemical to address that problem. In some cases it is important to know the volume of water you are trying to treat or the amount of the substance you are trying to remove. Sometimes if too much of a specific chemical is added it might poison the pond life. It is also important to know that in some cases once a chemical is added to the pond water, it stays in the water until it is removed or used up. Many chemicals do not dissipate in the water and they don’t evaporate. Because of this, when you add different chemicals in the future you may have a chemical reaction between the two that could result in undesirable or harmful conditions. Removing one chemical from the pond is not easy. It can be removed by water changes but to remove 99% of the chemical by water changes would take a change of 8.9 times the volume of the pond. For example, if you changed 5% of the pond volume once a week it would take 178 weeks to get 99% out. That is approximately 3 and a half years! The same would hold true for medications.

A word of advice; be careful of anything that you put in your pond because it might be there for a long time. Of course there are some chemicals that disappear fairly quickly. Ozone is one of these. It has a half life of 4 minutes in ideal conditions and much less in any other conditions. What, you ask, is ozone and what does it have to do with a pond?

As ozone is one of the newer ideas being used in the pond world I will explain it as simply as I can. Oxygen normally forms molecules as two atoms of oxygen (O2) but ozone is one molecule of oxygen with three atoms of oxygen (O3). Because the third atom of oxygen, ozone is always trying to get rid of that third atom. Because of this it is a very powerful oxidizer. In fact it is the second most powerful oxidizer known to man. How does that apply to a pond? It means that it can oxidize any organics in the pond. In fact it can be so efficient at oxidizing nitrite to nitrate that the bacteria that would normally take care of this can die off due to a lack of nitrite for them to eat. A word of caution, ozone can be a very dangerous compound and should not be used unless you know what you are doing.

As stated earlier, the next article will cover biological filtration.

©2004 all rights reserved to Mike White

PART 9: Planning for Pond Expansion

When is the best time to plan for the next new improvement to the pond? With most of us, our life is so busy that there is no good time to plan for what we want to do months down the road. We have enough trouble just planning for the next weekend. Most of us will wait until spring or summer is here and than start thinking of what we want to do for the pond. By this time we are so under the gun to get something done quickly that we really don’t think enough about it or investigate it well enough. So we either do nothing and put up with the problems we have, or do something and next year end up in the same position of trying to correct what we just did. So don’t forget the 6 p’s.

What are the 6 P’s? “Proper planning prevents piss poor performance”. To most of us our pond is a sizable investment that we gain considerable enjoyment and relaxation from. But I don’t think I have met a pond owner yet that did not want to change something on their pond or the pond itself. If it is going to get done right, now is the time to start planning for it. It is far easier and cheaper to change something on paper than when you start digging and find that electric line going to your house right in the middle of new pond expansion.

How do we get started planning? The first step is to put together a wish list of everything you would like to see changed. It could be a very simple like changing the look of the waterfall or as complex as changing the entire pond.

Next determine if you plan to do the work yourself or hire it to be done or a combination of both. Even if you are thinking of doing the work yourself it might be a good idea to get a quote or two from a professional. Many professionals don’t charge for a quote so other than a little bit of your time, you have nothing to lose. The person giving you the quote might have some ideas that you hadn’t thought of.

How do you find a reputable professional? You already belong to an organization that has a wealth of knowledge, so use it. Ask people that you know in the club and you should get some names of good professionals.

Now is the time to start to put together a budget for the project. Most of us have limited funds with which to work and we may not be able to do everything on the list this year. We might have to do things in stages. Like everything else in this world pond equipment is going up in price. In fact it is going up very quickly. Almost everything used in pond construction is an oil based product so the prices have skyrocketed. As an example, liner that is commonly used from last year at this time to now has gone up 12% at the wholesale market. Expect things to be more expensive than you anticipated.

Based on your budget, you now have a good idea of what part or if you can do the whole project at this time. If you are doing any part of the project by yourself you will need to lay out the steps necessary so the project can be done efficiently and with the least waste of time and expense. If you are doing part of the project yourself and the other part by a professional you will need to make sure that your part is done when necessary. By breaking down what needs to be done it will allow you to determine those steps that need to be done at the same time. It also will prevent you from doing something before a necessary previous step. With the project broken down into steps it will help prevent forgetting things and help you determine how much time the project will take.

Then you should put together a time line of all the different activities that will take place. Remember that things always take longer than you think. If you are going to use a professional for all or part of the project remember that they have their schedule and commitments that they have made. The earlier you get in touch with them the more likely that your time line and their schedule will line up. So when trying to find a professional one of the things to determine is how responsible is this professional. Are they going to do what they say they are going to do, when they say they will do it? Maybe your time table is flexible and if they are late by a few weeks that is no big deal or maybe you are planning a graduation party in the middle of June and the person you hire says they will be done the first of June. If the person you hire is reliable everything should be okay but if they are not then who knows. If you have enough to worry about already, you don’t need to add things to the list. This is also true if you are doing it yourself. If the project is going to take place over a week or more make sure that you leave time for weather and other things that may come up.

If you are doing part or the entire project by yourself then you will need a bill of materials or a list of things that you will need to complete the task. You already have a budget and a time line of when you will need things. This step is to insure that you have what you need on budget when you need it. Nothing is worse than to get to a point and find out that you don’t have something that you need and when you go to get it you find out it is on backorder for a week or more. That can be a very costly mistake in terms of the project. This is also true of any equipment that you may need to rent or acquire.

You should now have the project somewhat under control. Remember if you are doing the work yourself you have more control. If you have friends helping you make sure to line them up early. If you are going to have a professional do part or the entire job, then the earlier you get that scheduled the better. A professional can get booked up months in advance. Also remember that a professional is going to require money down at the start of the project. This is normally 1/3 to ½ of the total amount of the quote. Remember any changes requested that are not in the original quote will normally change the final bill.

©2006 all rights reserved to Mike White

Oh my. Oh dear.

Either the Pond Fairy has struck again in the depths of the night, or you’ve just paid your local landscaper a wad o’ cash to combine the fatal, ineffable trio of water, plants and fish in your very own back yard. You need to know one incredibly important fact. It is central to the entire hobby of water gardening.

THERE IS NO CURE.

Once you have settled down at dusk by the side of your new pond with a glass of fine wine in one hand and a great trashy novel in the other, you become aware of a feeling you were not expecting. No, it isn’t inner peace and serenity. You need a Buddhist monastery for that, and you look lousy in saffron anyway. It’s not pride and satisfaction, either. That lasted just about until you had to pull out and rinse off that mucky filter pad on your submersible pump, and discovered one of those expensive fish the landscaper sold you dead in the skimmer looking like a live grenade. No, what you are feeling is the common malaise and unrest that all ponders feel once their current water feature is installed, paid for and running. It is the eerie and ominous, all-pervasive psychic effect of the Three Laws to which you are now, like all other water gardeners, frog fanciers and koi keepers, immutably subject. You find yourself looking at that prize rose bed and reflecting that it’s getting really tough to keep up with those darn Japanese beetles every year. The lawn is just too much trouble to keep groomed. Those annual beds are just so …tacky, somehow. Wouldn’t a perennial bed be easier? Maybe a more natural setting, with bombproof aquatics and blooming marginals? You find yourself looking at every home you visit and saying to yourself : ” I’d put the pond…there!”. Well, bucko, once The Laws have you, there is no escape, so you might as well know what you are dealing with.

The First Law:

There Is Always A Better Fish.

Yes, I know your original intent was to build a lovely, low-maintenance water feature with a minimum of critters to worry about, but that baby koi at the fish show was so cute and he really isn’t all that big. Surely the filter mat and lava rock will be able to handle the load. Oh! Look at that 2 year old fish on this website…we need something to eat all those mosquito larvae, anyway.

And so it goes. Pond people are natural enthusiasts and incurable optimists. The pond just isn’t right somehow without something to come wriggling up to the surface when you shake the can of fish food. It’s real easy to get overpopulated. And fish grow. Fast. Real fast. Which leads us naturally to…

The Second Law:

There Is Always A Better Filter.

Shortly after buying your umpteenth fish and introducing him into the pond, you realize that the population does not look happy. They are sulky and lethargic. They are not eating and they look unhappy. If you are smart and thinking ahead, you have already bought a good test kit for ammonia and nitrite, and have just found that your pond scores high on both. That lava rock at the top of the falls just isn’t doing it, folks, so it’s time to do your research. There is an answer for every filtration problem, even if you didn’t know that the question even existed. It is important to understand that there are three kinds of filters (chemical, mechanical and biological) and each has its place in The Great Swamp of Ponding.

Chemical filters (charcoal, zeolite and the like) remove chemical impurities and pollutants from the water by binding them to their own chemical structure. They are usually used in short-term or emergency situations, such as sales or show vats, but have no place in the outdoor pond. Most water gardens and koi ponds combine mechanical and bio-conversion filtration in one or more containers of varied design. Pond filtration is one of the most rapidly developing and hotly debated aspects of the hobby. Gravity-fed vs. pressurized. To UV or not to UV. Lava rock or Siporax ( or Tuffy sponges?). The choices are endless, and what may have worked for Cousin Earl in his 25,000 gallon indoor showplace will be a gurgling disaster in your 550 gallon stream and pool.

The solution is to ask questions, and never entirely believe any of the answers until you have seen them work. Find other hobbyists (look for gardening clubs, hobbyist websites like this one (gasp!), koi clubs) and pick their brains. Don’t be shy. Any experienced water gardener and koi fancier has been where you are right now, has done the fix, bought the t-shirt, and then used it to plug the leak in the hose that was supposed to be leakproof. Describe what you’ve got in a gathering of pond people, and you’ll hit 14 “bore-buttons” simultaneously. Ponders love to talk, especially about their disasters and how they fixed them. Your solution is Out There.

A caveat, if you will, before going on. Never believe a filter manufacturer when he tells you what the “capacity” of his filter is. For the safety of your critters (which become family members very quickly), cut the claims by half, and install accordingly. Your goal in filtration is to expose every molecule of water in your pond to your bio-converter at least once an hour. Make sure your pump is up to the strain and your filter and piping can handle the flow.

Oh, too much splash? Fish growing fast? No room for that lily or lotus? Ah, Grasshopper, you have just run afoul of …

The Third Law:

There Is Never Enough Water.

Almost every water gardener starts small, thinking that small size means low maintenance. This is not entirely true. A pond that is shallow will be more susceptible to wide shifts in temperature and pH, and is more subject to catastrophic reactions to pollutants and other toxic events, especially with high fish populations. Ask any ponder; almost without exception, he or she will tell you that the showplace you are viewing in her idyllic back yard is actually the fifth pond on that site (if you count the two water lilies in the muck bucket!), and if they had really been thinking during construction, they would have dug down another foot, at least.

A true pond owner is eternally greedy for gallonage. Big volumes give you stability and room for fish and plants, and if designed right, also can be made routinely almost (note the word “almost”, it’s a killer!) self-maintaining. Ponds are very much like model railroad layouts. There is generally at least one glitch needing repair, and there is always one more improvement that will make it just perfect. If a boat is a hole in the water that you pour money into, you can achieve the same sense of accomplishment with a pond, which is a hole in your yard full of water that you pour money into. Your chances of drowning with a pond are marginally smaller, and you don’t have to travel to do it! A true ponder will tell you that if you are still mowing grass, you do not have enough pond.

Never be afraid to look at your current water garden and envision change. It is what this hobby is all about. See you at the next koi show!

DrBob

Pond Detective, here. It was a dark and stormy nigh…er- day, and I’d been been called pondside by a worried koi keeper. One of his fish was dead and the others were clearly distressed. His fish (who weren’t talking) had all been cleared the week before by the local Infection Police, so we both knew it wasn’t an infectious problem. Aside from alien invaders, he had a problem. My job? Detect it (Dum-da-dum-dum).

After obtaining as accurate a history as is possible, including pond cleaning, feeding, water changes, water source, filter maintenance, and testing history, I’ll quietly observe the pond and the behavior of the fish. I’ll look at the appearance of the water, at the flows for rate and direction, at the inlets to the pond and sources of aeration, and take deep sniffs of the air around the pond.
It is a quiet, kidney-shaped bare-liner pond with a small waterfall and a gentle, meandering stream. Minimal in-pond vegetation. It is edged with cobble rock; no limestone flags that I can see. I estimate its volume at about two thousand gallons with a maximum depth of 3.5 feet in the general area of the pond furthest from the falls and stream. The water has a slight green tinge, and the healthy “watermelon aroma” is absent. The 20 large koi are sluggish, and appear unhappy and clamped. They are grouped at the falls end of the pond and are not schooling. Even small noises or disturbances at the edge of the pond seem to stress them. One or two of them flash occasionally.

Hmmm. A water quality issue, eh? Well, the routine is what gets results, as my old beat sergeant used to say (before he took up surrealist bonsai). Observation complete, time for the first test.

First test: Chlorine/Chloramine. Our area relies almost entirely on the Chicago municipal water supply, obtained from Lake Michigan and depending on the season and the whims of the Water Department, heavily chlorinated. It’s a common mistake when doing water changes: a high volume change (replacement of water lost in cleaning or added during bottom cleaning with a hose-powered “vacuum”) introduced directly into the pond without aeration or use of dechlor.

Test : Real pink on Chlorine, less so on Chloramine. Preferred would have been zero (clear).

It’s also easy to fix. If there isn’t an ammonia problem, you can use sodium thiosulfate crystals or Novaqua. Amquel is a better all-round choice. I’ll warn the client that tap water needs to be treated as it goes in or his fish’s gills will look as bad as his lungs do (did I mention that he’s a two pack a day guy?) and for about the same reason.

I’m not gonna act on this one until I get more information, though. Might regret it.

Dimensional warp. Someone must have reversed the polarity of the neutron flow. Either that, or leprechauns have been doctoring my test kits with merthiolate. The area gives an existential hiccup and…

Okay. Chlorine/Chloramine negative. I guess he isn’t totally stupid. Out comes the DO meter and we do a quick read at multiple areas of the pond. A quiet pond is probably an oxygen-poor pond, and there are no air stones anywhere to be seen (our owner feels that too much water movement disturbs the oriental tranquility of the ecology, and air stones don’t look “natural”). The only air-water interfaces I see are the pond surface itself, and the smooth sheet of the gently flowing waterfall.

Test: DO 4mg/L at water temp 75 degrees at the deepest point, 5.5mg/L at the point nearest the falls and stream. We want 7.0 or better.

Restraining the urge to advise our client to take up wolverine-breeding, we send him out to purchase a competent air pump and several large air stones and hose to link them. He is also advised to upgrade his water pump to put a more vigorous flow across his falls, and to interrupt that smooth, serene sheet with a bunch of jagged rock to enhance air-water mixing. Better yet, a home-built Bakki shower hidden in the rampant trumpet vine behind his falls would work even better. Got a set of plans right here.  Serenity be damned. His fish gotta breathe!

Twit.

Blerp. Another dimensional hiccup. Someone is really messing with the time stream around here. As soon as I straighten this guy’s pond out, I am going to prod some serious buttock. Might even have to get medieval on him.( Might have to go with Morris Dancing or three-field crop rotation. If he really gets me mad, it’s the Maypole for him…)

Right. Reset again. He proudly shows me the hidden bioreactor system behind the falls feed, and his DO at 75 F. is 11mg/L. Not the oxygen, then. Pretty classy system, too, and really well-hidden. Alkalinity next. A number of reasons for this. First, he’s got a very common setup as far as basic pond construction is concerned; a bare liner bottom and no source of carbonates. Second, he’s got a flashy, high-end filter system that depends on high-efficiency media in a small space. Third, he, like most koi keepers of my acquaintance, is way overstocked for the absolute volume of his pond and is relying on his space-age bioconverter to keep up with the load. I start to do the titration and he looks at me like I come from Mars. ( his kit consists of teeny-tiny tablets in impervious foil pouches. He’s never heard of Alka-whatzit and gave up trying to test his own water when he broke a tooth trying to open one of the childproof test containers.)

Alkalinity: 12 ppm Wanted: greater than 100. Preferably 140-150. Aaarrrgh. Filter crash! Need a bunch more tests: pH: 6.8 Want: 7.5

Temp: 75 F (about 24 C) (Can’t do anything about this, but it’s important)

Total Ammonia: 5.4 mg/L (Zero would have been nice!)

Unionized ammonia: 0.18 (Yeah, what he said!)

Salt: 1.88 ppt (Whew, finally something good. That’s about 1.5 lbs. 100 gallons and should take some of the stress off the fish. Better yet, I don’t have to mess with that now, and can take direct action.

Right. I’ve got 5.4 ppm ammonia in a 2000 gallon pond. I know that commercial grade amquel will take out about 1 ppm at a dose of 0.5 cc/gallon. I’m gonna need 1000cc x 5.4 ppm= 5400 cc of Amquel into this pond before I do anything else. (I also have powdered Amquel, but the conversions are a little complex, especially since what the manufacturer says it’ll do is not reflected by actual tests. It’s actually about two and a half times more potent than it claims!).

It’s been an hour. Amquel’s had a chance to work. Salicylate method Ammonia tests zero. pH has dropped to 6.6 because of the old-formula Amquel I’m trying not to waste. (The new stuff is supposed to be buffered). In goes a 5 pound box of Arm & Hammer Bicarb. Test after an hour or so and adjust the next bicarb dose to bring the alkalinity up above 125ppm, though we’ll want to go slowly from this point on to minimize stress on the fish as the pH corrects. Water changes will help too, but the salt and bicarb dosing will have to be corrected after each exchange.

The first thing we tell our client is that he may not feed his fish for a good two weeks, until he’s got some ammonia-nitrite bioconversion back, and after that only sparingly for another two weeks until his nitrite-nitrate bugs kick in. His old population checked out during the crash.

The time spent waiting for our chemical fix to work was spent giving our client a crash course in basic chemistry and biology, and then a list of suggested test kits that won’t frighten (or injure) him. Routine testing of Cl, pH, Temp, ammonia, Nitrite, DO and alkalinity on a regular schedule, and the use of salt and buffers as needed to lessen physiologic stress and stabilize pH should keep him out of trouble.

The most difficult thing to grok in this hobby is the blinkin’ awful interrelatedness of everything we do. Our fish interact with the water, the air, the filter, the feed…it goes on and on. Even after years in the hobby, we’re all still learning.

Humph. No more time glitches. Well, on to the next mystery. Pond Detective’s work is never done.

(Dum-de-dum-dum-Daaaaaa)

The Inherited Pond
-or-“Darling, what’s that hole in the back yard?”

It happens. A lot. You gotta move. New job, new kid, new career, new town. You find it, the perfect house, great construction, man-cave, kitchen full of new appliances, close to transport, roomy garage and a big back yard with a-ulp-pond. With fish. Realtor says “Ain’t it great? So soothing!”
Only one problem. Your total prior ponding experience involved falling into one at age seven while visiting Old Uncle Joe on his farm. Your remaining memories of that experience, including as they did the Attack of the Million Enraged Feral Chickens, fifteen pounds of mixed mud and blanket weed and an unfortunately-placed cow pie are mercifully dim. Suddenly you are the person in charge of a whole new ecology, with lives on the line.  The movers have been and gone. You live here. Now what?
Given the popularity of this hobby, it’s not surprising to find a pond in the back yard of every other house you look at while hunting. What you will do with what will either be an absorbing avocation or a monumental headache needs to be part of the process of deciding before you put your money down.
Think. Do I want a new hobby? Given the complexity of successful water gardening (at the easy end) and koi keeping (at the hard end), are you willing to commit the time and money involved? As pretty as that water feature looks, there’s probably a considerable bunch of infrastructure hidden away somewhere on the property. The prettier the pond, the more complex the works. This hobby tends to eat all your other hobbies.
Do I have the resources to support this hobby? Water gardening is not cheap. It’s been said (by boaters) that a boat is a hole in the water that you throw money into. A pond is a hole in the back yard that you throw water and money into, and you probably have to pay for the water. The only advantage that ponding has over boating is that your risk of drowning is slightly lower. Electricity for the pumps and filters. Supplies for water testing. Fish. Food. Plants. Landscaping and re-digging when you find that the pond is just too small. New pumps. New filters. New pipe. Lights. Remember that the closest hobby to ponding in addiction and character is model railroading. Like a model railroad layout, a pond is never, ever actually finished.
Sounds awful, doesn’t it. It is not. This is one of the most absorbing and rewarding activities around, if you let yourself get involved, and your fellow enthusiasts are some of the nicest and most helpful folks you’ll find anywhere. This hobby will stretch your mind and you will never be bored.
So. Set the scene. You want this property. Pond and all. What do you need?

1.    You need some assurance that the pond is in current working order and has not been abandoned since the previous owners left town mysteriously three years ago closely followed by the FBI, NCIS, LSMFT and KGB. If what you see is a stagnant puddle that smells bad, a bulldozer may be your best option. If the pond is in operation and it smells like fresh cantaloupe (assuming that you are house-shopping in the summer), go to step 2. If it is deep winter, and all you can see is seven feet of snow, go to step 2, but with caution.
2.    Talk to the owners. It is still their pond and, most likely, they did most of the design and upkeep work. They know where all the tools, switches, valves and pipes are. They know what leaks and when and where the most common failure points are and what to do about them when they fail. Ask if they are members of a koi club or water gardening society. If they are, join before you move. Go to meetings and ask questions.
3.    Get an operating manual. If the previous owners have not written one, make it a condition of the sale.
4.    Before you move, and before the previous owners split for parts unknown, have them run through the daily, weekly and/or monthly maintenance rituals. Take notes and pictures. Record the conversation. Ask them about visitors to the pond. Not just the neighbors. Ask about the wildlife. Depending on where this pond is, you could be dealing with anything from raccoons to herons to mink to alligators. Or drunks.
5.    Inspect the infrastructure for age, condition and accessibility. Change is the ground state in ponding, but you need to know where you are starting from. A run-through by a competent electrician is a good idea too.
6.    If there are fish, look at them. Are they healthy, active critters or do they look damaged or sick? Are there too many of them in the pond? Does the water look clean? How does it smell?
7.    If you have a friend who is familiar with the hobby, make sure he or she looks at the pond with you. If you have hunted down a koi club before you moved, get one of the members to look things over. Many clubs have at least one or two members who have trained as Koi Health Advisors and can give you advice that is based on fact rather than opinion or hearsay.
8.    Read, read, read. This website has articles and FAQs that cover practically every aspect of the hobby. There are loads of other resources available on the Internet. Do not go into this hobby blind.
9.    No pond is perfect. There were probably design and construction errors made during building and peculiarities that have crept into the system over time. A clean, compact layout is the mark of a professional builder that has not been played with. A chaotically tangled mess of valves, pipes, tanks and motors is the sign of a pond that has been modified multiple times and has-adapted. Both systems probably work. Guess which one needs a Ouija board to operate?

It sounds complex, but if you are prepared for it you’ll never regret getting involved in this fascinating ecological exercise. It is addicting, absorbing and, at the end of a stinky, hot day at work, it is the best thing ever to sit by the pond, reveling in the knowledge that your huntin’, shootin’ and campin’ buddies have to travel 600 miles to find a spot by a body of water with no sanitation which they must share with the bears, cooties and blackflies. You have the falls, the stream and the fish right there. Need a beer? The fridge is just a few steps away. With Wi-Fi!

The Inherited Pond-Part Two

-or- “Wait, what? I didn’t know that was back here!”

Aaaaaand this is the second and way more common scenario. Great house, fantastic yard and nobody mentioned the pond. If they did, it was called a “low maintenance attractive water feature” in the realtor’s blurb. You move into the property in the middle of the worst winter since the IceMonster attack of ’08 and the icecap has receded enough to reveal…THE BLACK LAGOON! It might be inhabited…

The previous owners are long gone leaving no forwarding address and the realtor has either sold out or burned down. Now what?

The decision tree is pretty simple at this point. Do you want to be a ponder or not? Either way, you’ll need to know what’s in there and what’s available from a support standpoint. Are there resident livestock? Is there a pumping facility or perhaps filters hidden somewhere? Are there tools, nets, pumps or pipes? It’s time to look around.

Start with the pond itself. First off, how big is it? I had the privilege of talking to a new ponder this past weekend who had just moved into a rural property in the southern exurbs to find that he was now the proud owner of two 30,000 gallon ponds and several hundred koi (and God knows what else). His learning curve is gonna be really steep, but with those volumes, he’ll have time to get a grip on the problem. Ponds that size mostly run themselves. Most of what we run into is considerably smaller.

Now look around the pond perimeter. What is there in the way of infrastructure? Is this just a hole in the ground, or is there a waterfall and a skimmer? Can you identify pipe runs, and if you can, where do they go and what is on the other end? Is there a shed or a storage structure nearby? What treasure lies within? Maybe filters? Maybe an operating manual? Be careful. There might be a Grue.

Next, how does it smell? If what you get is a distinct aroma of rotten egg, you can be reasonably certain that there will be nothing living beneath the surface. The presence of hydrogen sulfide implies anaerobic breakdown of organic materials, and the dissolved gas is toxic to just about anything except bacteria from the abyssal trench. Water that has no bad odors suggests hope, regardless of how it looks.

In either case, you do not start by poking around with sticks or nets. At best, you’ll frighten or stress any inhabitants that have been lying low all winter. At worst, you’ll stir up whatever muck is lying on the bottom, deposited by winter storms, wind and whatever. Stirring it up releases whatever has been developing in the sludge, and it’ll be toxic. You need to drain that pond.

You’ll need a high-capacity submersible pump for the job, and a Home Despot-equivalent sump pump is a good choice. If you think that the pond harbors live denizens, you’ll need a net and someplace to put them, at least temporarily. A 100-250 gallon Rubbermaid horse trough from Farm ‘n Fleet works well here, especially if you are planning to continue in the hobby. It’ll end up as your isolation tank. Pump out and discard the water, you’ll be replacing it anyway. Or not.

As the water drains, living denizens, if any, will become visible and can be transferred to your holding facility. Anything left on the bottom of a mechanical nature (pumps, pipes, or if you are really lucky, a bottom drain) will begin to give you an idea of how the pond worked and how well it was designed. If you are having the usual Ponder’s Luck (a corollary of Murphy’s Law) what you’ll get is sludge and if you are REALLY unlucky (Murphy was an optimist), the bottom will be covered in gravel, and maybe Jimmy Hoffa. The fact that there was water in the hole suggests that the liner, whatever it is made of, was intact, at least to the top of the water level. Do your best not to damage it.

STOP. Decision time. DO YOU WANT TO BE A PONDER? Are you willing to subjugate yourself to the tyranny of the THREE LAWS of PONDING? If not, install the sump pump in your basement, use the horse trough as a patio water garden and call a landscaper in to remove the liner and fill in the hole. Plant flowers and veggies. Be happy. If you decide that the pond is your future, clean out the bottom, get rid of the mucky gravel, refill, dechlorinate, hook up whatever infrastructure you can find, transfer the livestock, if any, back to the pond and start studyin’ up. The rest of this website is a great place to start. The learning curve can be steep, but it’s worth it.

Oh, the THREE LAWS?

• There is always a better fish.
• There is always a better filter.
• There is NEVER enough water.

Beware.

Bob Passovoy
May, 2016

I Think I Want A Pond…

I really believe it is hard-wired into our brains. There is something about the sound of rapidly moving water that strikes a chord in the deepest parts of our souls. Perhaps it is the (barely) upright ape in us that links that sound with basic survival, a promise of life, coolness on a hot day, and the chance, if we are quick and lucky, of dinner.

Whatever the reason, the desire to have moving water in your immediate living space has hit, and you are beginning to do the research. As you start, there are some questions you should ask.

1) How much time do I want to spend?

This question has implications both as you start up and as you persist in the hobby. If you are not careful, water gardening can easily absorb large portions of your limited leisure time and has the tendency to eat other hobbies if not closely supervised. Folks with two jobs, a young family, housework and a host of social obligations should be very careful here, and limit themselves to a pot garden at most. Those with an aversion to muck and wet should stop reading now and take up knitting. Model railroaders had better have finished work on their layouts and rolling stock, because this hobby is addictive, and their current setup will be their last, unless they can transfer their affections from HO scale to Garden Railway.

2) How much money do I want to spend?

No question here. The bigger it is, the more it costs to build and maintain.

3) How much space do I have?

This is a no-brainer if you live on the 73rd floor of a high-rise in downtown anywhere. You are only at risk if you have enough grass to mow in a protected area around your house. If you have enough grass to require a power mower, you are really in trouble. Rider mower? Uh-oh. Full-time groundskeeper and staff? Oh dear oh dear oh dear.

4) What do I want this water feature to do?

Is it just the sound of moving water you want? Do plants figure into the concept? What about animal life? Fish? Frogs? Possums? Raccoons? Deer? Herons? Neighbors? Building inspectors? Ordinance Control? If you want fish, what kind of fish are you thinking about? Goldfish are small, practically bombproof and easy on the ecology, but are considered by practically every backyard predator to be delicious and easily caught. Koi are big, beautiful and impressive, but also expensive, demanding and sometimes challenging to maintain.

How much time do I want to spend?

This question has implications in both the construction and maintenance phases of pond ownership. In construction, the obvious conclusion is that if you buy something that comes out of the box, fits on a tabletop and plugs into the wall, it’ll have instructions that say “Just add water”. You’ll end up with something that may look nice and goes “burble” (and occasionally “bing”), and won’t take up much of your time at all. It will, however tend to get ignored over time, run dry and burn out. These mini-features come under the “funny once” category of water gardening, and if they support wildlife, it wasn’t the wildlife you were thinking of.

If you are looking for an outdoor feature, but are both time and space-challenged, (Over-employed high-rise dwellers come to mind here.) a satisfactory compromise can be attained with a barrel garden. Half-whiskey barrels and convincing plastic look-alikes can be had at most garden centers, and liners for the wood barrels are also easily found. A small pump and fountain (or falls) arrangement, some rocks and small aquatic plants and even a goldfish or two complete what can be a very satisfying and relatively low-maintenance water feature.

Any advance beyond this point suggests outdoor yard space and a larger commitment of construction and maintenance time. Now is the time to stop, think and decide just what it is that you want this water feature to do.

Decision point one: “I don’t want to deal with critters, I just like the sound of splashing water. I think waterfalls are neat.”

The neatest solution to this situation is an arrangement I saw at the Midwest Pond and Koi Society’s trade show last fall (2004). It combined a liner-based waterfall of the “build-it-yourself” type, cascading down into a bed of coarse rock. This can obviously be anything from limestone landscape rock to carefully hand-chosen Wisconsin cobble rocks. The secret to the arrangement is that the waterfall cascades onto the rocks, which are contained by a large heavy-gauge plastic basin. At the bottom of this basin (about two to three feet deep) is a high-efficiency submersible pump protected by a cover. The basin is buried to its edge below the falls and filled almost to the brim with water, the level stopping just below the top of the rocks. Water cycling over the falls empties into the rocks and vanishes, to be pumped back up to the top of the falls. No open water, no mosquitoes, but plenty of places to stick plants between the rocks, and lots of room for creative rock arrangement in a small space. The small footprint of the feature keeps the amount of digging to a minimum and the major investment of time will be in arranging your waterfall rocks on the liner. Most of your ongoing maintenance time will be directed at maintaining your water level so your pump does not run dry, and fall drainage to prevent water freezing in your pump and water lines.

The key thing to remember here is that you will be digging a hole in your yard of significant depth and width. Even though it will present zero drowning risk to even the clumsiest of neighborhood drunks, it still puts underground structures in the way of your shovel. Call your local Utilities Tracking Service (in the Chicago metropolitan area it is called “Julie”). They will come out, and at no charge, will mark off where all the buried water, gas and electrical lines run. Do this first before beginning any dig.

Decision point two: “I don’t have a lot of time or space, but I’d like something pretty, with fish.”

Check with “Julie” first. Then touch base with your municipality, if you have one. Owners of farms and other rural properties do not have this issue. Most urban and suburban communities have very specific ordinances governing placement, depth and protection of in-ground water features. Many also require building permits. It is much easier on everybody if these details are dealt with before the first shovelful of earth is moved.

The decision to add fish to a water feature puts you into a whole new category of this hobby. Although shallow versions of this type of pond (18 inches or less in depth) are considered by most communities to be “water features” not requiring extraordinary protective measures, the livestock have needs that must be met, and the open water that this feature contains will also require maintenance.

To be very basic, fish eat and excrete. The products that they excrete are toxic to them, and if not disposed of in some way, will eventually kill them. In the wild, fish live in large bodies of water fed constantly by springs, streams or rivers. There are thousands of gallons of water available for each fish present. Your backyard pond offers no such luxury. Most “beginner” ponds range between 50 to 250 gallons (especially if they are of the preformed “dig and go” type) and are closed, recirculating systems. Maintenance of water quality adequate to sustain fish health will require either daily large-volume water changes or some form of biofiltration.

Very simply put, a biofilter is just a box full of something with a large amount of surface area (media) that beneficial bacteria can attach to and do their job. Water from the pond flows through it and the bacteria on the media convert the toxic ammonia produced by the fish to nitrite (also toxic) and then to nitrate (relatively nontoxic, but great fertilizer). Most biofilters also contain mechanical filters (brushes, mats, fine gravel or sand) which remove larger solid waste and floating debris. These can be home-built using food-grade plastic drums or garbage cans as the container, or bought complete with all sorts of horns and whistles from any number of manufacturers. If there is a caution to be raised with regard to any of these manufactured products, it is that the manufacturer will always overstate the filtering capacity of his product. View any statement on the box such as “…for ponds up to xxx gallons” with the gravest suspicion, and divide the “xxx” by at least 2.

Remember also that municipal water is treated to kill bacterial contaminants, usually with chlorine, chloramines or both. While these render the water safe for you to drink, they also will kill off your biological filter and injure your fish’s gills. Any pond with fish and filled from the garden tap will need to be pre-treated with a good dechlorinator.

The decision point “pretty” also implies plants. Aquatic and marginal plants are an essential part of the backyard pond ecosystem, adding shade, cover and beauty to the mix. They also provide a small amount of biofiltration, and will be important in removing ammonia from the water. Ammonia is toxic to fish and creates another problem: algae. Hobbyists deal with both floating algae and hair (or string) algae every season as a matter of course. Both are present everywhere in the pond environment, and grow rapidly in the presence of sunlight and food (ammonia-otherwise known as “fertilizer”). Growth of both types of algae can be limited by the presence of actively growing aquatic and marginal plants, but small ponds can’t support a large enough plant population to do the job and still leave room for the fish. In the case of floating algae, the kind that turns your pond to “pea soup” in late spring, the easiest solution is an ultraviolet light unit placed in your water line between your filter and your inlet to the pond. String algae is another issue, and is dealt with elsewhere.

The most basic, cheapest and easiest to install in-ground ponds are the so-called “pre-formed” type. You can see these for sale at any home and garden outlet. They have the advantage of being easy to install and run, requiring a minimum of digging or piping. They are frequently sold as kits, and may include a pump, a fountain or falls arrangement, and occasionally even a filter. From a time and money standpoint, they are very attractive.

These rarely exceed 200 gallons in capacity and have a number of drawbacks.

•    They come in a limited number of shapes and sizes. This limits your ability to fit it into your landscape plan.
•    The kits are usually under-filtered, and will support only small populations of aquatic life.
•    The pumps are frequently designed to run small fountains and often do not move adequate volumes of water through the filter to allow for proper bioconversion. They also tend to be fairly flimsy, jam easily, and rarely last more than one season. They are inevitably submersible pumps, which present a constant maintenance problem as well, requiring that you pull them out almost daily to clear the inlets.
•    They are necessarily shallow, rarely exceeding 18 inches in depth. This makes them easy targets for predators. Raccoons, possums, herons, bullfrogs and other common predators all love these types of ponds. The fish in them tend to be slow and delicious, and tend to come towards any disturbance in the water, hoping to be fed. It’s better than McDonald’s!
•    The small size of these units limits your options with regard to fish. Goldfish do well. Anything bigger, such as koi, will suffer and die.

More time on the install, but…

For all practical purposes, flexible liner-based ponds are the most adaptable and most easily maintained ponds going. They can be designed to fit into any space, incorporate any feature you want, go to any depth, and if designed with forethought, can be easy to maintain, durable and almost self-sustaining from an ecological standpoint. A wide variety of liner materials are now available ranging from the old reliable (but heavy) butyl rubber to lighter, thinner and very durable space-age plastics and polymers. Since the design and building of this type of pond is entirely your choice, it allows for absolute freedom in your choice of pumps, streams, waterfalls, fountains and filters. For specifics, we refer you to Mike White’s excellent series of articles on pond construction elsewhere on this site.

How much money do I want to spend?
The fact that you are even reading this article implies that you are willing to spend something. How much you will actually unpocket will depend on your imagination, resourcefulness, energy, and the intensity with which this hobby will bite you. At the point at which it transmutes from an interest to a hobby, you begin to spend money. When it goes from hobby to enthusiasm, you can multiply your willingness to spend by a factor of at least five. When you slide from enthusiasm to obsession and become “koi kichi” and your spouse or S.O. is ready to drown you in your ever-expanding construct, you’ll need a lotto hit or two or three new jobs.

The Ebeneezer Scrooge Option
Get a pot out of your cupboard, put a piece of celery, some water, and that hokey plastic goldfish you picked up at that garage sale into it. Done.

One Notch Up
Container water gardening is a popular low-cost and space-thrifty option to ponding that allows cliff and bungalow-dwellers access to at least some of the fun of ponding. While these systems do not have the volume necessary to support koi, they will handle a couple of goldfish and a surprising variety of aquatic plant life for minimal cost. What is essential here is a small but durable pump arrangement with enough output to keep the water in the container circulating briskly. Aeration can be supplied either by a small but turbulent stream bed or an aquarium-grade air pump and stone. These tend to be inexpensive, and your container can be anything that’ll hold water and won’t leak, tip or go crashing through your floorboards. Careful attention to water quality is essential here. The major failing that these systems have is chronic under-filtration.

…and Another Notch!
Preformed ponds can be had at almost any garden supply place these days, and, if cleverly installed, can look quite good. They tend to range between 75 and 200 gallon capacity and rarely exceed 18 inches in depth. They are easy to install, and many come as kits with pump and small biofilter included. Be cautious about these systems. The manufacturer almost always overestimates the capacity of the system to support aquatic life, and even a couple of enthusiastic goldfish can overpower the filter in a couple of spawnings. These systems also are not sufficient to support koi, and worse, are very difficult to defend from predation. Raccoons love them, especially if they have (as most do) plant shelves. They knock the plants into the pond, hunker down on the comfy seat thus provided, and chow down on your fish. Possums and wading birds are also a threat, and the more rural you live, the worse the problem will be.

…One Notch Further…
Liner-based ponds can be any size, shape and depth, and if you are willing to do the work of planning, digging and piping yourself, they can be built for surprisingly little money. An article in Koi USA about three years ago detailed a complete construction plan for a liner pond, including a home-built skimmer, falls and barrel biofilter which cost, at that time, about $1200. Given the design and materials, this cost has not escalated much over the intervening years. As you get into the 800-2000 gallon range, koi keeping becomes possible, and the deeper you go, the better koi will like it. Most experienced hobbyists consider a depth of four feet to be a minimum, and prefer six to eight feet if they are planning on having really big fish. Oddly enough, maintenance and running costs decrease as the pond becomes deeper and larger, mostly due to increasing stability of pond chemistry and temperature. A well-designed deep pond is also much easier to defend against predation. Raccoons can’t fish when they’re dogpaddling, and herons can’t hunt when there is no place for them to wade.

It’s important to remember, however, that your community may have views about your project, and have probably backed them up with ordinances. These are probably easily viewed at the Public Works Office in your local Town Hall, filed under “Stuff” beneath a pile of 1944 calendars in the bottom drawer of a file cabinet in a small alcove in the fourth sub-sub-basement with a sign on the door that says “Beware of the Leopard”. As hard as it may be, staying in compliance with your local rules and regulations from the beginning saves time, energy and heartbreak later on. Remember to call your local Utilities Tracking Service BEFORE you dig. Hitting the neighborhood’s 220-volt service line with your shovel while standing in damp soil is no fun.

Doing the digging, wiring and piping yourself cuts way down on the cost, but remember, all that dirt has to go somewhere, and dug dirt takes up a lot more room than the hole from whence it came. You can use some of it to construct the hill that your stream and falls will cascade down, but neighbors tend to get cranky when the grade level of their veggie garden mysteriously rises two feet in one night. Time to cultivate that “innocent” look. (Mike White’s articles on pond building become required reading about here.)

Bam!
At the high end of this scale is the option of having a professional with heavy digging equipment and a horde of manpower come in and do the gruntwork for you. What becomes important here is in the selection of this kind of help. Ask around at other ponds about the contractors in your area. Many landscapers will offer to dig for you, but if they do not have actual ponding experience, they will screw it up and you will inevitably be disappointed, left with an unworkable, badly designed hole in the ground and no recourse and backup. Your contractor should have experience in pond construction and be willing to give you addresses and phone numbers of prior customers. He should be willing to help you design and build the pond that you want, and not a “cookie cutter” design that happens to be easy for him. He should be familiar with piping and filtration systems, or should know someone who is.

Don’t talk to just one contractor. Get multiple bids and multiple plans. Above all, talk to other water gardeners. Be sure you know what you want your pond to be and to do before you dig. A plant and frog fancier will not be happy with an 8 foot deep formal koi pond, and a certifiably koi-kichi enthusiast can’t use a winding 18-inch deep stream for anything other than eye candy.

If you are going this route, you should be thinking of volumes of 4000 gallons and up, and be planning on spending at least $7000 not counting pumps and filtration. As with any project of this magnitude, there is no upper limit on what it is possible to spend. The best local example of this exists (beautifully!) in a northern suburb of Chicago, where a hobbyist doubled the square footage of his already large and gracious home with a very deep, very large and very well-filtered indoor pond. He takes every advantage of this and scubas with his fish frequently.

Salt? Again? Do we use it or not, and if we do, what for? What we think about salt in our ponds changes as we talk to different experts in the field of aquaculture, and some of the finest arguments I’ve gotten into lately seem to have salt at their origins. There is no question that the versatile compound of a poisonous gas and a toxic and explosive metal has a place in the management of our ponds, and it is time once again to review its current place in our ponds.

A healthy koi does not need salt. Neither does a healthy pond. Koi are carp and carp are fresh-water fish. Their physiology allows them to pump free water out of their tissues back into their environment and maintain very much the same tissue concentrations of salt and water that all living creatures on this planet enjoy. To do this, they expend energy, and being cold-blooded and dependent on the water temperature around them to determine how fast their metabolism turns over, that energy budget is limited. That being said, salt has been shown to be helpful in the management of stressed and injured fish, presumably by lessening the osmotic difference between the inside of the fish and the outside environment, allowing the fish to clear more free water with less energy expenditure. This may allow more of the available energy to be devoted to the koi’s immune response to infection or parasitic infestation, or to devote to wound healing. Ulcers may also be helped with salt, since they represent a hole in the barrier between the inside and outside of the fish. A healthy koi uses its skin, scales and slime coat to keep free water out, and that protection is lost when an ulcer forms. Salt in the water reduces the free water diffusing through the ulcer and in turn reduces the amount of water the fish has to pump back out.

How much to use is open to argument, and you’ll get a different answer from every expert you talk to. The numbers you hear the most range from 0.15 to 0.3 per cent salt, with some advisors going as high as 0.6 per- cent in isolation tanks for very sick fish. Concentrations as high as 2 lb of salt in 10 gallons of water are frequently used as a dip to terminally discourage parasites.

An extensive online search on the subject proved interesting. Google Scholar yielded 133,000 articles incorporating pond and salt. None of them were in any way related to backyard koi ponds and most of them dealt with construction and maintenance of power-generation from non-convecting salt ponds. Narrowing down to keywords “Koi, salt” got me 22,000 articles, only one or two on subject. Those from actual scientists dealt mostly with using high-concentration salt baths as a dip or disinfectant. The only mentions of salt use in ponds fell into three categories. The first set dated from my last search about three years ago and centered around a series of articles by Brett Fogle, who runs MacArthur Water Gardens, an online commercial operation that sells (you guessed!) pond salt. He was all for constant and consistent use. Interestingly, newer articles and posts from him have changed their tone, and he’s a lot less enthusiastic about it now. The second set represented the majority opinion in the articles, posts and blogs that I sampled. Salt is useful as an anti-parasitic dip and an early spring treatment for protection against high nitrite levels. It is NOT recommended for constant treatment in the pond. The third set recommended avoidance of the chemical entirely, except as a high-concentration dip for transported fish, or fish fresh out of the mud pond, the sudden osmotic stress serving to explode most of the parasitic load on a fish on contact. It was interesting to note that the geographical locations of these sources were generally places that did not experience winter.

Salt’s ability to kill parasites is problematic. Epistylis, Trichodina and Ichyophthirius (Ich) will be inhibited (but not eradicated) at concentrations of 0.3% and this effect is often temporary. Fish with leeches, Anchor worms and Costia require individual dipping in 2% salt baths as well as 0.3% concentrations in the pond water, though repeated or extended exposure to salt tends to generate tolerance and resistance to treatment. Dactylogyrus and Gyrodactylus (gill and skin flukes) laugh at salt (a sniggering Dactylogyrus is a nasty thing indeed) and many of the effective treatments require low or zero salt concentrations to limit toxicity.

There is no question in anybody’s mind that salt is vital in early spring. As the populations of nitrifying bacteria wake up and start the conversion of ammonia to nitrite to nitrate, it rapidly becomes clear that the crew that handles ammonia-to-nitrite are the cheerful early risers, while the nitrite-to-nitrate gang seems to need several cups of strong coffee and a couple of extra weeks to get going. During that high-risk period, salt provides protective chloride ion to compete with the nitrite in the fish’s blood. The necessary 30:1 ratio of chloride to nitrite is easily supplied by a 0.2% salt concentration, maintained until nitrite levels drop to zero.

Frequent water changes and very limited feeding will help keep the problem under control.

Okay. If you are going to use salt, it is critically important that you know how to manage it. There are RULES.

Rule 1: Salt in your pond is there forever. If you have evaporative losses, the concentration goes up. The only way to get rid of it is to do water changes. Many, many water changes.

Rule 2: Salt kills plants. Sometimes this is a good thing. Salt in the pond in early spring can limit algae blooms, although it won’t eliminate them entirely. Concentrations higher than 0.2% will wipe out your tender aquatics and keep your water lilies from thriving. Watering your garden with salted pond water gets you the Sahara desert.

Rule 3: You must know how much salt you have in your pond. At all times. This means you need a reliable test kit or a meter. These are widely available and will generally report levels in either % or parts per thousand. Any test kit that reports concentrations in “color zones” or wide ranges is not worth the money you paid for it. For reference purposes: 1 ppt = 0.1%

Rule 4: Change salt concentrations SLOWLY. This means both directions. Slow up, slow down. Bring your salt levels up gradually over a period of days to your target. Bring them down over a period of weeks with water changes.

Rule 5: Don’t leave salt in when you don’t need it. ‘Nuff said.

Rule 6: Know how much salt to add before you add it. Hence the formulas.

Rule 7: Use the right salt. 99.9% pure or “Solar Salt” or “Blue Bag” salt. NOT pelletized or water-softener or road/sidewalk salt. Pickling salt is okay but way expensive and is for pickles, not fish. Pond salt or “aquarium salt” from the pet store is a flat ripoff. Iodized salt is expensive, and the iodine will injure gill tissue, just like its near-relative, chlorine (Look two spaces down from Cl in your handy-dandy Pocket Periodic Table). What you need is available from your local Home Despot equivalent for about 4 bucks per 50 lb. bag. It is evaporated sea water and contains other minerals (magnesium, calcium and others) which will act as buffers to stabilize your pond’s pH and will also supply trace minerals essential for koi health.

The “Not Rocket Science” Formulae:

Lb salt to add = (total gallonage of your system/120) multiplied by (desired salt conc. in ppt – current salt concentration in ppt)

For example:

Pond system volume: 4400 gal
Desired salt concentration: 1.5 lbs/100 gal = 1.88 ppt
Current salt concentration = 0.6 ppt

Lbs salt needed = (4400/120) x (1.88 – 0.6)

= 36.666 x 1.28 = 46.99 lbs salt

What is ultra-cool about this formula is that you can mess with it and get a formula to estimate the gallonage of your system. This is where an accurate test kit is critical.

Total gallonage of your system = 120 x Lb salt added / the difference between the salt concentration (in ppt) before and after you added the salt

To use the formula, you need to measure the salt concentration before and after you add a known amount of salt. Remember to give the salt enough time to thoroughly disperse throughout your pond. One day is just dandy. The amount of salt you choose to add will depend on the size of your pond and the accuracy of your test kit.

For example: A new pond. Medium to kinda big size. Good salinity meter from Aquatic Eco-Systems.

Starting salt concentration: 0.2 ppt

You add: 40 lb salt

Wait one day.

Final salt concentration: 1.0 ppt

1.0 – 0.2 = 0.8 ppt

Total gallonage = 120 x 40 / 0.8 = 6000 gallons

“Not Rocket Science”: Defined as the amount of math I can do without having to take off my shoes and socks.

So, here’s my recommendations:

Use salt sparingly, just like you would any other pond additive.

Monitor levels carefully. Don’t dose too high or change too fast.

Leave it in long enough to achieve your goal, then get rid of it with water changes.

© 2013 Robert D. Passovoy, MD