Definitive Quarantine & Treatment - by Michael Singleton Quarantine & Treatment Tanks

From time to time, you will need to be able to keep fish outside of the main pond, for either quarantine or treatment. What is often overlooked is the simple fact that this containment must be as "fish friendly" as the pond itself, if not more so. While an inadequate Q (quarantine) or T (treatment) tank will protect the fish in the main pond from the fish in the Q or T tank, those isolated fish stand little chance of survival.

Since the Q and T tanks have so much in common, I'll speak of them as if they were indeed, one in the same. Point of fact, for many people, these two types of isolation tanks *will* be one in the same. For now, lets call them by a single name, the QT tank.

The idea of quarantining new fish before adding them to the main pond should not be considered as anything less than mandatory. Failure to see it that way puts your entire collection at risk. It doesn't matter if your fish are "pond mutts" or high-end, show quality Koi. There is no reason to risk loosing them all to an "imported" disease. People will tell you that they never quarantine new fish. About the only thing they have going for them is pure, dumb luck. And that will not last forever. Sooner or later, they will learn the hard way.

There is more than one reason to quarantine newly acquired fish. The reason most people are aware of is to give you time to determine if the fish is healthy and parasite-free. But consider how your fish came to you.

If they are imports, they've likely had a rough time of it. The real high-end Koi don't have it so bad, as they are pampered all the way from the breeder, to your pond. But the majority of imported Koi will have been stressed beyond belief, before you get them. They will have been moved a number of times, without being fed, or allowed to recover from the previous move. And then there's the long flight in a crowed bag. Once in the country, they may undergo several more moves before the dealer gets them. A good dealer will allow the fish time to recover from all that stress, before offering them for sale. A large number of them will sell them as quickly as possible, however.

Domestic Koi won't go through quite as much of that, but still enough to place the fish under a considerable amount of stress. *Any* Koi bought at a Koi show should be thought of as a "high-risk purchase." This would be due to the obvious stress involved with the fish being moved and being kept in very crowded conditions in water of doubtful quality. Then there is always the chance of cross-contamination with water from the other tanks at the show. This can be as obvious as children (or child-like adults) putting their hand into every tank they come to, or something less obvious, such as airborne mist from the inevitable splashing that occurs.

The Quarantine Period is a *Recovery Period* that lets the fish "rest up" and get back to "normal." The post-shipment period finds the fish very stressed out and this stress *will* suppress the immune response. This shipment stress and it's effect on the fish's ability to fight disease is the underlying cause of the *myth* that imported Koi are somehow "less hardy" than domestic Koi. Send a domestic Koi on the same journey and it will wind up the same way, severely stressed and ready to die with the least provocation.

Give these fish an environment that allows them to feel safe, with excellent water quality, and they *will* recover. Just like a person with "jet lag," they need to "rest up and catch up." Their immune systems will begin to function again and if kept in a facility that is parasite-free, with well filtered water, and nothing to cause them to go into a "flight or fight" mode, they will do well. The most important thing they will need during this phase is *stability*. No changes in *anything.* Change equals stress and they've had more than enough of that! Your QT system needs to be able to supply them with that stability for the first week or so with minimal intrusion.

Note: All QT tanks should be netted, to keep frightened fish from jumping out, as well as to keep predators out and foreign materials from dropping in. Providing some sort of cover for the fish to hide in will reduce the likelihood of jumping, as well as making the fish feel more secure. But this cover should not be something the fish could land on and be stranded, should it decide to jump anyway.

After that first week (or two,) the more commonly thought of part of quarantine can begin. This is where you start looking for things that could threaten your main population of fish, such as on-going disease or the presence of parasites. Care should be taken to accurately *identify* the specific disease or parasite that needs attention, so that the *least* intrusive treatment can be given. If none have been found, then simply *observe* the new fish for several weeks. If after three or four weeks nothing has been found, good! But don't add them to the pond, just yet.

With the newly discovered diseases and harder to kill strains of parasites, many have begun to advocate prophylactic treatments. These are treatments for parasites not actually observed, but "just in case" they are present and missed during a microscopic exam. I'm beginning to find myself thinking more along those lines, myself. But if this is to be done, it should be after a long Q period that has the fish being fully recovered and better able to withstand the treatment. *Not* something done during that first two weeks of "recovery."
(See note <http://koivet.com/html/articles/articles_details.php?article_id=195&category=9&name=Techniques>)
The next thing that should be done and often is not, is the introduction of an expendable "test flyer" (or two) from the main pond, *into* the QT tank. That's right, move one or two fish *from* the pond, *into* the tank with the new fish. Why? This will let you find out if the normal "background" bacteria that are normal to your new fish, will be a problem for your existing fish. All fish have "resident" bacteria that they are "used to." Put a child in a new school, and you should not be surprised to find him/her come home with a cold, or at least a simple case of the sniffles. In a short period of time, he/she will get over it and will have adjusted to the new "background bugs." Same with fish!

The fish from the pond will introduce the pond's background bacteria to the new fish, and they will also have the chance to sample the new fish's background bacteria. So, you have to watch *all* the fish in the QT tank. If after two weeks of cohabitation everyone seems fine, start doing partial water changes in the QT tank, replacing the removed water with water *from* the main pond. Once satisfied that nothing new is going on with the new fish once the majority of the water has been changed, then you can move them to the main pond.

One new twist to the equation is the fact that both KHV and SVC (viral diseases) have temperature "triggers." Things being the way they are these days, serious consideration should be given to including changing the water temperature at a controlled rate to avoid thermal shock to the fish, moving the water temp into the active ranges of both diseases. After the incubation period has passed and everything still looks good, the temp must then be returned to match the pond water temp, again, in a controlled manner, avoiding temperature shock. With any luck at all, your pond will already be within the active range of one disease, so that you'll only have to worry about the other. (As if one wasn't enough!)

Doing all this can easily run the Q period well past that oft quoted "3 week" minimum. But the longer, the better. And it should be obvious by now just *why* the QT tank needs to be so much more than a minimum holding tank. It must be every bit as good of an environment as the main pond, itself. And it must be able to keep that high level of quality, for as long as needed.

Now, if this QT tank is being used for treating a fish, or several fish, it still needs to be a high-quality environment, but not for such an extended period as when used for quarantining new fish. If you were treating the fish with injectable antibiotics, the fish would typically be returned to the main pond in five days, or less. At the end of the injection series, you should be seeing definite signs of healing. There is no need to keep the fish out of the main pond after this point. In fact, the fish will heal much quicker when returned to the main pond.

Many simply catch the fish and inject them, without removing the fish to a treatment tank. What is not widely known by hobbyist is that a larger percentage of whatever antibiotic is injected will be passed into the water through excrement, virtually unchanged. This introduces a low-level of antibiotics into the water that can expose pathogenic bacteria in the pond, to a sub-lethal dose. And in smaller ponds where dilution is incomplete, that may be one way that drug-resistant diseases can come into being.

Another benefit of using a treatment tank for antibiotic treatments is that the fish will under less stress, as it should be relatively simple to catch them for the injections. Chasing a single fish around a large pond will not only stress the fish being sought, but the rest of the population, as well.

Water temperature is critical during antibiotic use! At a temperature of 65*F or less, antibiotics are practically useless due to the fishes' slow metabolism. Ideally, you want the water temperature to be in the 74*F to 78*F range. It is relatively easy and inexpensive to warm up a QT tank, especially when compared to heating an entire pond. Large aquarium heaters can be used, or stock tank heaters for larger QT tanks. I've heard of one person that built a QT tank that incorporated a waterbed heater under the liner! (If you think about that one for a minute, it won't sound quite so crazy.) Just remember that warmer water will hold less oxygen than cold water, so aeration is important.

Keeping the fish in a QT tank during treatment also makes it much easier to observe the fish for changes in condition. This will make it easier to assess the effectiveness of a treatment and to decide early on, if a change is required should it not work.

Other treatment protocols are of short duration. Having a QT tank ready is handy for short-term treatments, such as Chloramine T or Oxolinic Acid. Here, you can balance the volume of water between two criteria. One, large enough to safely contain the fish for the duration of the treatment and Two, small enough to keep the treatment from being cost-prohibitive.

Some use a QT tank to use one type of treatment on the fish, while doing a much harsher treatment on the pond, itself. It does little good to treat fish for a problem, and then return them to the exact same conditions that allowed or caused the problem, in the first place. Simple concept, but surprisingly *often* overlooked.

Some examples of what can be used for QT tanks:

Stock Tanks. These can be Poly Tanks, Rubbermaid tanks, or a similar tank, often found with the lowest price at farm supply stores. The cone bottom tanks can be set up to be nearly self-cleaning, very easily.

Show Tanks. These can be a bit more expensive, but are excellent for this use. Do keep in mind that some treatments may stain the tank. Their advantage is that they can be folded up when not in use, for storage.

Purpose Built Tanks or Ponds. These could be small ponds of any type, such as a landscape timber pond, with fish kept in them to keep the biofilter active. But you must be able to remove the resident fish when you need it! If you aren't going to keep fish in it, then you should devise a way to cover it, to keep it empty and clean, while awaiting use.

Improvised Temporary Containment. By this, I mean something as simple as a wire fence used to support a flexible liner. One company I know of sells these in a kit form, from quite small, to very large. If you have the room and are into "self-abuse," you can simply dig a hole and drop a liner in, even a replacement swimming pool type.

"Kiddy-Pools." I'm not including those shallow wading pools for very small children, unless you need to quarantine aquatic plants. But the larger pools with rigid sides *can* be used. If you can find one with high sides that isn't *too* large, it can be useful. The high sides, combined with a net cover, reduce the chances of loss through jumping. Much talk has been directed at the possibility of a chemical added to the vinyl that keeps algae from forming, which would be a problem for fish. But I've never actually seen a pool that had such an additive. To be safe, read every printed word on the package, just to make sure. You might even want to give the manufacturer a call, if a number can be found.

Maintaining Water Quality

As previously stated, the water quality in a quarantine or treatment tank *must* be as good as, or *better* than in the main pond. For very short-term, bath-type treatments, this is no problem. If the volume of water is sufficient, all you need do is provide aeration. For longer periods, some form of filtration will be required. Maintaining water quality through water *changes* is not a good idea. Again, think of "change" as "stress."

Water changes can produce unwanted variations in water temperature, and can make sustaining specific concentrations of a chemical treatment difficult. (Even salt.) Unless the change is in the form of a flow-thru system, it guarantees variations in water *quality*. A flow-thru system would make many chemical treatments impossible.

One of the easiest ways to filter a QT tank is with a chemical filter. At least one type of activated carbon filter is sold as a complete "system" for small ponds. It consists of a submersible pump with a fountainhead (useful for aeration) and a box containing a carbon pad on the pump's intake. I've used a modified version of this setup, several times.

The modification consisted of removing the carbon pad and the "solids filter" pad from the box. A piece of plastic window screen was placed in the box, and loose carbon granules were poured in. The screen was cut large enough so that it could be folded over the carbon, holding it in place. I left just enough space in the box to cover the carbon with a sheet of synthetic air filter material and was just barely able to put the lid back into place. This gave me much more carbon in the filter that what comes in that pad. You might be able to fit more than one pad in the box, if you'd rather not mess with loose carbon.

The problem with a chemical filter using activated carbon is that it *will* remove most any type of bath treatment. If you are going to use a bath treatment, you will have to remove that carbon filter. If you use zeolite instead of carbon, you can run into the same problem, plus you won't be able to use an elevated salt level, either. The salt can cause the zeolite to dump whatever ammonia it has absorbed.

However, if you are going to be using primarily injectable antibiotics and/or topical treatments, the chemical filter can work well for you. Any chemical treatment that you would use in a pond, that requires bypassing a biofilter for a short term, would be available to you in this QT tank. Instead of bypassing the chemical filter, you would simply remove it from the pump's intake. The pump would be kept running, to provide circulation and aeration.

Should you decide to use standard biofiltration, all the "rules" that apply to the pond's system, apply to the QT tank, as well. The filter must be fully "cycled" *before* fish are added. Trying to establish a biofilter while quarantining fish is a short cut to disaster!

Biofiltration

You have a number of options. If your QT system will be using a sponge filter, it can be set up and running in the main pond. Here, it will cycle and add to the pond's filtration. (Too much filtration is not enough! Sound familiar?) Likewise, most types of bio-media can be place somewhere in the pond or filter system where water will flow through it. When needed, it can then be removed from the pond and placed into the QT' tank's biofilter. Another method would be to set up a small bead filter on the main pond and move it to the QT tank, when needed.

A submersible pump, or an airlift can power the sponge filter. (Making a home made sponge filter <http://www.koivet.com/html/articles/articles_details.php?article_id=88&category=15&name=Filtration>) The simplest form of the latter would be a large, open cell foam sponge, with a hole in the center, running all the way through it. A pipe with an end cap is set down into that hole. The part of the pipe that is inside the sponge should have a number of holes drilled in it. An air stone is placed in the bottom of the pipe. The pipe should extend from the bottom of the sponge, to a point just below the surface of the water. Air bubbling up through the pipe will bring water with it, drawing it in through the sponge. This makes for a nice biofilter that also helps aerate the water and will capture solids, at the same time. It requires a depth of about 18 inches to work really well.

The sponge filter will have to be cleaned, from time to time. I've found the best way to do that is to put a plastic fish bag around the filter while it's still submerged. Push the bag against the sponge to remove excess water, without squeezing the sponge. This makes it easier to lift it from the tank. Once out of the tank, the sponge can be dunked in a bucket of pond water to remove the solids. A gentle squeezing may be needed, but be careful not to *over clean* the filter. You do not want to remove much of the biomass when cleaning the filter. This type of biofilter should not be confused with a sponge-type of mechanical prefilter. The sponge will naturally collect solids, but it's primary function is to provide surface area for biofiltration bacteria, just like the media any other type of biofilter.

An oversized sponge also can be used as a prefilter on a submersible pump or just about any water intake. Care must be taken to see that this prefilter is not allowed to clog to the point that it impedes the supply of water to the pump. Starving a pump can greatly reduce it's life expectancy.

Sponge filters and just about any small biofilter that would be suitable for Q or T tank purposes, can be "stored" in the main pond to provide additional biofiltration, while keeping them cycled and ready for use in a Q or T tank situation. This way, you'll never find yourself short of a cycled filter when you need one. Also, Doc Johnson has some good information on "rapid starting" biofilters <http://www.koivet.com/html/articles/articles_results.php?article_id=64&category=15&search_term=bioseeding>, on the KoiVet web site. If you don't want to keep a "spare" biofilter in the main pond, you can use his information to get the new biofilter up in running in short order.

The small bead filter <http://www.aquadynamite.com/shop/details.php?productId=4&parentId=10&catId=10>, or even a small, high-rate sand filter offers both mechanical and biological filtration. But just like the main pond's filter, *any* biofilter will function more efficiently when it is not expected to do both jobs associated with pond filtration, mechanical and biological.

The trickle tower is a good type of biofilter for quarantine tank use, as it adds greatly to the oxygen content of the water. I consider the Low Space Bioreactor to be a "submerged analog" to the TT, and quite suitable for QT systems. But neither of these biofilters was designed to provide any mechanical filtration, at all. *None*. Both must have a good mechanical filter in-line, ahead of them.

A quarantine tank of newly purchased Koi would *not* be the proper place to try out one of the "bugs-in-a-bottle" concoctions to cycle a biofilter, unless you've used it before and have seen it actually *work.* One bacterial additive product I *do* like to use in a quarantine situation is LymnoZyme <http://www.pondrx.com/shop/listing.php?parentId=31> and double-dosed at that. LymnoZyme will not prevent all your bacterial problems, but it will greatly reduce them.

If you have a UV that can be used on the QT tank, by all means, use it. I'm not so sure I'd run out and buy one just for this, however. If you do, consider getting one at least *twice* the size recommended by the manufacturer, and run it with only *half* the flow rate that would normally be used with a UV that size. This way you just might get into the range that would offer some serious bacteria killing properties.

However, do be aware that many treatments require that the UV be shut off while the treatment is active in the pond. It may "de-activate" some treatments, and could cause some chemical compounds to become toxic to the fish.

Aeration

Aeration, or, getting oxygen into the water, can be accomplished in several ways. The most effective way is by using a spray bar as a water return from the filter system. A spray bar is nothing more than a capped pipe with a series of holes drilled into it. Instead of a single column of water gently returning to the tank, the spray bar gives you a number of small "jets" of water that impact and disrupt the surface of the water.

A foaming fountainhead is nothing more than a venturi. These fountainheads add a lot of aeration to the water. I use one attached to a short length of garden hose to aerate water from a well, when adding water to a pond.

Adding air stones is always a good idea, but they do not add as much oxygen to the water as a spray bar. One additional benefit from placing an air stone in the bottom of a tank is that the rising column of bubbles will help "turn the water over." The surface disturbance produced by that column of bubbles can give the fish a sense of security, in that the disturbed water is hard to see through. And that surface disturbance is where most of the aeration from an air stone really takes place.

A submerged venturi placed on the water return can be used. Some water treatments can be poured into the air intake of the venturi, giving you a good, fast method of mixing it into the pond water.

Solids Removal

Most of the time, solids removal in a QT system can be accomplished quite simply, by putting an over-sized sponge filter on the submersible pump's intake. This can be cleaned, as often as needed, without regard to removing any "beneficial bugs," as it's purpose is mechanical filtration, only.

Larger QT systems may require a mechanical filter more along the lines of what would be found on the main pond. But since the QT system is usually going to be much smaller than the pond itself, methods of solids removal that might not be practical on the pond can and should be considered. These methods include cartridge filters, bag filters, and sand or diatomaceous earth filters.

Solids production should not be as pronounced as in a pond, but solids removal cannot be ignored. If you are using a biofilter such as a pressurized bead filter, you may not need to add mechanical filtration, *provided* the bead filter is sized properly, knowing that it will be performing *two* totally different functions at the same time. But a bead filter, just like any other biofilter, will work more efficiently when it is fed mechanically clean water. This holds true in any application, QT or on the main pond.

Heat

As stated above, water temperature is critical when using antibiotics. They simply will not get the job done when the water is too cold! You must be able to keep the water in a QT system within the range of 74*F to 78*F range, for the best results. Colder than that, it will be almost impossible to beat a bacterial infection. At higher temps, water simply is not capable of holding much oxygen and oxygen depletion can easily occur. Remember that some treatments can consume *large* quantities of oxygen!

In Summation

Quarantine and treatment tanks should not be considered a "luxury" item. They need to be thought of as an integral part of good Koi keeping practice. These systems can be as simple or as elaborate as you care to make them. But the basic requirements do not change. They must WORK! There are two different hobbies you can choose from, Koi keeping and "fish fixing." Ignore the need for proper quarantine and treatment tanks, you'll eventually find yourself as part of the latter, rather than the former version of the hobby.

Koi keeping is a *lot* more fun!

Mike S.

Spring Hill, FL

 

 

AKCA™s Koi Health Advisor Program A brief fact sheet     The Koi Health Advisor  program  is now an ongoing program that was originally sanctioned and sponsored by the Associated Koi Clubs of America  starting in March of 2001. The program seeks to increase the pleasure and satisfaction of koi hobbyists by improving and maintaining the health of their fish. The program offers training on good koi husbandry to interested and qualified hobbyists. It is hoped that the graduates of the Program will not only improve their own koi keeping but also teach and assist others where the law allows and will provide a link to qualified veterinarians if and when the need arises. The course is open to any member of an AKCA associated club that is not a koi professional, i.e., not an owner of a business, or employee or representative of a business, that sells koi or that sells products or services used in koi keeping. To date, the Program has graduated about 140 KHAs. There is no tuition for the course. The AKCA has and will continue to fully fund the preparation and teaching of the Program as a way to give back to and support the hobby that supports the organization. Students will, however, be required to obtain their own equipment and supplies and provide their own transportation, meals and lodging to attend the (one weekend) laboratory session. It is estimated that the out of pocket cost to the individual student for participating in the program will likely be between $200 and $1000 for the first year (the approximate time to complete the basic course including attending the lab) and depend on a number of factors including the travel distance to the lab and amount of equipment and supplies that the student already possesses.   A class runs for July 1st of a given year to June 30th of the following year. However, qualified students may enroll until Dec. 31st of the starting year as long as they commit to finishing with that class, i.e., finish by June 30th of the following year. The course is taught entirely over the internet with the exception that all students are required to physically attend one hands-on lab. Labs are likely to be conducted at, and in conjunction with, the AKCA™s annual Seminar held traditionally on about the last week end in June. Each student is required to attend the lab in order to graduate.   The course can teach virtually anyone to be a better koi keeper.  The basic course has eight sections taught by advanced hobbyists and veterinarians: Pond Design  by Burt Ballou Filtration  by Chris Neaves Basic Water Chemistry  by Norm Meck Nutrition  by Chris Neaves Anatomy & Physiology  by Spike Cover Health  by Sandy Yosha, PhD, DVM KHA/Hobbyist Interface  by Spike Cover Lab  by Sandy Yosha, DVM; Tim Miller-Morgan, DVM and Spike Cover   Tests are given after each section and the criteria for passing a given section test is set by the individual instructors.. The instructors are very supportive and everyone who has stuck with it has passed the tests and completed the course.  Additionally all instructors are available by email and there is a closed bulletin board for Q&A by the graduates, students and instructors.    Graduates of the Program are issued a Certificate and a pin. In order to maintain their certification, graduates are required to take a specified number of continuing education  units every two years. CE courses are sought, promoted, and in some cases the preparation is financed, by the AKCA. Credit is also given for completing approved courses that deal with koi health but are outside the Program.   The ability to achieve advanced levels of certification within the Program is being explored.   This brief fact sheet is intended to provide a general overview of the KHA Program and is not a complete description of the Program. Additional information, including how to sign up for the KHA program, may be found on the AKCA™s web site at http://www.akca.org (follow the KHA links) or by going directly to the KHA links page at: http://www.akca.org/kht/kht.htm   Additional information can also be obtained by contacting: Tim Czech, 65blcc@gis.net

 

Quarantine – the nuts and bolts

By Spike Cover

January 10, 2003

The reason for quarantine is simple. It’s to protect your existing koi. You have probably put much time, effort and money into assembling a collection. All that may be jeopardized if you introduce new fish without adequately determining if they carry with them a serious disease.

Quarantine is a forced isolation and it is important to know that a bad system can be deadly to the inhabitants. If parameters are not adequately controlled, the detrimental effects can be as disastrous as any disease. This means that all critical parameters should be monitored regularly and adjusted if and when necessary. The most important parameters are ammonia, nitrite, pH and temperature. The best way to control the first two is to have an adequately sized and mature bioconverter in the system. The good news is that, when done correctly, it is probably your best protection from new diseases.

Other articles have written on the philosophy and conditions of quarantine. This article intends to focus on the physical characteristics of the quarantine systems themselves. As with any system, a decent quarantine system needs to be adequate for the intended purpose. This means that a system that is adequate for six-inch tosai is not necessarily adequate for a 36-inch jumbo.

Quarantine systems can take many forms. What are described below are three systems that have been physically built and have been run for periods from 6 weeks to nearly 6 years. Each can no doubt be improved but each has proven to work and if you are looking for a place to start, one of these three may suit your needs.

Note: as an alternative to the DIY filters and bioconverters described and shown, very suitable commercial units are available. If you choose to purchase such a unit, it is recommended that you buy one that is rated for volumes 3 to 5 times that of your Q-system. This "over sizing" is for two reasons: first, we need to run the Q-system faster than a "normal" pond in terms of turnovers rate and the filter system needs to be able to support the flow; second, since there is no standard criteria for rating filters, manufactures tend to advertise performance toward the high end of the range.

A minimum system

In the extreme, one might keep a new fish for a few weeks in a container of water with AmQuel^®, Ultimate^®, or other ammonia inhibitor, an air-stone and frequent water changes (think: koi show methods). However, we shall start with a system that also provides for bioconversion and temperature control. It is a system that I have built at least five times (probably more) and preformed filter-startup tests using the configuration numerous times. I have successfully kept fish in these systems for 6 weeks having started with virgin bioconverter medium.

This first system is very low-cost (~$65), low volume (25 to 30 gallons) system that is adequate only for small fish (up to a maximum of 10"). It consists of a 32 gallon Rubbermaid plastic container; a DIY trickle-tower (TT) bioconverter made from a 2 gallon plastic bucket and lid, lava rock and a PVC stand-pipe w/fittings; a submersible pump; some tubing; a submersible aquarium heater, top netting and a PVC support for the bioconverter. Recommended, but optional, addition is insulation on the outside (particularly on the bottom).

Here’s a picture of the system

 

 

 

 

 

 

 

 

 

 

 

And a close up of the trickle-tower bioconverter ("TT")

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Schematic of TT

As an alternative to the DIY bioconverters shown, very adequate commercial units are available. If you opt to buy them, it is suggested that you purchase a unit rated for 3 to 5 times the size of your system.

Here are the details and some tips:

● "Blow out" from a mature bioconverter (disease-free system) added directly into TT should aid in starting the bioconversion.

● Raise electrical plugs off the ground and cover from the weather (a plastic bag works well).

● Change about 5 to 10 gallons of water each day adding dechlor and/or ammonia binding chemicals if necessary.

● If the nitrites start to rise, add ¼ to ½ pound of rock salt to the water (add 1 heaping tbs salt, 3 cc dechlor and 3 cc ammonia binder, e.g. AmQuel, per 5 gallons of new water). Try to insure that the new water is within 10° F of the container water temperature if 5 gallons is added during a water change and within 5° F if 10 gallons are added with the intent being to not changing the overall water temp more than 2° F with the water change.

● Test kits required are ammonia (salicylate method), nitrite and pH. Aquarium Pharmaceuticals makes adequate kits that are about $3 to $6 each and may be purchased from PetSmart or any of several other suppliers. If you don’t already have tests kits, I recommend you buy and use these test kits.

 

● The container may be filled to within a few inches of the top if a cover net is in place (highly recommended). Sheet metal or wood screws inserted into the outside of lip of the container can provide attachments for the netting.

● Optional insulation such as polystyrene foam (Styrofoam^®) on the bottom and bubble wrap around the outside of the container will help to conserve heat in colder conditions.

● When connecting the tubing to the pump and TT bottom fitting, heating it in a cup of hot water makes connection easier.

● Put about 40 or so ¼" holes in the lid of the TT.

● Don’t forget to put a few outlet holes in the bottom of the bucket

● You can upgrade to a Rubbermaid "Brute" 44 gal plastic container for and additional $24 (price = $33)

● Roddy Conrad and Duncan Griffiths tell me the TT will probably work better if there were a lot of holes in the sides of the bucket – my guess is that ½" to 1" holes would work well.

 

 

 

 

 

 

 

 

 

Here are several systems during a filter test

 

A variation on this system can be had by replacing the TT bioconverter with a cube (9" to 12" on a side) of open-cell foam with the submersible pump located in a center pocket cut into the foam (foam plug reinserted in hole), a short piece of tubing extending up thru the foam and with a saw-tooth cut bottom (cut saw tooth so that water can more easily enter the bottom.) I used a Rio 600 pump successfully.

List of materials (assumes you purchase all items new and not on sale – items may be purchased from Home Depot and/or Aquatic Eco-Systems – and that you have the tools to do the required fabrication)

 

Item	Qty reqd	Price (approx)	Extension
Plastic trash container 32 gal Rubbermaid "Roughneck"	1	$7.88	$8
2 gal. bucket	1	1.97	2
Bucket lid	1	0.89	1
Lava rock – 1"- ½ ft3	½ sack	3.97 (full sack)	4
~200 gph submersible pump	1	15	15
½" ID x 5/8" OD x 24" PVC tubing	2 ft	0.25/ft	1
150 to 300 watt submersible heater	1	19	19
½" MPT x ½" hose barb – nylon fitting	1	1.36	1
½" MPT x ½" slip - PVC fitting	1	0.27	1
½" x ½" slip-slip 90° - PVC fitting	4	0.19	1
½" sch 40 PVC pipe	6 ft	0.83 (10 ft)	1
#6 x ½" stainless steel sheet metal screws	8	0.78/pkg	1
Netting	~4 sq ft	7.67 (7’x20’)	8
PVC glue – 4 oz	1	2.12	2
Total			$65

 

 

An intermediate system

The next system is suitable for fish up to 16". It is ~125 gallons and cost about $200. It incorporates some redundancy (for safety) and has pre-filter elements.

Tank, siphons and heater

 

Bioconverter & pump

 

 

 

 

 

The system w/o the plastic sheeting cover

 

Wrapped (covered) tanks

 

Schematic

 

Details:

● For smaller pumps (200 to 400 gph), use ¾" PVC pipe and fittings for the siphon. Use 1" PVC pipe and fittings for larger pumps. I’ve used Rio pumps, 800 to 2100. The outlet tubing (from the pump) needs to be sized based on the outlet fitting of the pump.

● Be sure to anchor the flexible tube that returns the water to the tank from the bioconverter so it doesn’t "get loose" and pump the water onto the ground.

● Saw cut several slots (1/3 of the way thru the pipe on about 1" centers) in the bottoms of the three drain pipe sections.

● Siphon fitting that are not submerged need to be glued otherwise they leak air and the siphon is broken.

● The plastic file boxes don’t weather well (sun damage) so put a something over them to keep the sun off – green or black garbage bag work.

● Raise electrical connections off the ground and cover with a plastic bag.

● Use the same water testing recommended above with the minimum system

● I’ve used this system a lot and not had any fish get out w/o netting on top (but I used the plastic "tent" on top). However, as sure as you try to get by w/o it, you’ll loose a fish. Enough said?

List of materials (assumes you purchase all items new and not on sale)

Item	Qty reqd	Price @ (approx)	Extension
Tank	1	75 to 25	$75 to $125
Filter (plastic file) box	1	4.75	5
Open-cell foam – 4" thick	2 ft2	8/ft2	16
Matting – 1" thick	2 ft2	3	6
Pump–200 to 700 gph	1	15 to 40	15 to 40
Filter stand-make from 1"x 6"x 6ft fence board	1	2	2
Siphon/drain – make from 1" PVC pipe	10 ft	1.98/10 ft.	2
PVC fitting 1" T	2	0.49	1
PVC fitting 1" 45°	2	0.79	2
PVC fitting 1" 90°	6	0.49	3
PVC glue- 8 oz	1	2.12	2
Heater – 250 watt	1	19	19
Insulation – bottom – ½ -1" thick Styrofoam – 4 ft x 4 ft	1	5	5
PVC flex tubing – pump to tank	3 ft	0.32	1
PVC ftg – ½" T	2	0.25	1
PVC ftg – ½" 45°	2	0.35	1
Cover support - make from ½" dia PVC pipe	10 ft	0.82/10ft	1
Plastic sheeting – 0.7 mil 9’x12’	1	0.98	1
Netting – 7’x20’ Birdblock	5 ft x 5 ft	7.67	8
Screws - #6 x ½" sht mtl – stainless steel	8	0.78/pkg	1
Total			$161 to $236

 

 

Advanced system

This system is suitable for virtually all sizes of koi and has several opportunities for variations. The system described here is one that is also in the back of the AKCA Guide to Filters and Pre-filters. It is a 500-gallon system and can be assembled for between about $800 to $1000 plus options.

Here are some details and hints:

● The system works best on a substantial level surface.

● Insulating the bottom with a Styrofoam boards not only works well but it help guard against damaging the bottom of the tank.

● A show tank with net hooks is VERY convenient.

● Insulating the outside of the tank with covered fiberglass (attic) insulation works well. The black-poly covered insulating can be held in place with a rope around the outside that is pulled up like a draw-string.

● Insulating the tank on all sides (including the filter and bioconverter) will reduce the amount of energy required to heat the system.

● Use a 1.5" slotted pipe (saw cuts on the bottom – 2" apart) as a bottom drain in the tank. Cap one the open end.

● All "trimmings" from OC foam when cutting and shaping can be reduced to ~2" cubes and put in large barrel under the main piece of foam.

● You can make your own 3" outlet fitting (from the bioconverter back to the tank) using male and female threaded fittings (PVC or ABS) and silicone gluing them in place.

● Flame oxidizing (with torch, electric match, etc.) around the barrel where the silicone glue will attempt to seal the 3" fittings to the barrel. This will aid the glue adhesion to the polyethylene and is done by just running the flame over the surface.

● A 3" elbow on the outlet of the bioconverter allows for directed circulation, e.g., clockwise, counter clockwise or neither (straight down) – cut hole with 3.5" hole saw.

● Water changes are encouraged. Minimum would be 10% per day. This is one place where more is better and up to a maximum of 40% per day is good (preferably done on a drip-in & over-flow out basis). Don’t forget to dechlor your new water!

● Use of a cover net is mandatory. Be careful not to have any holes in the net (this is advice gained the hard way!)

● Put the heaters in the pre-filter so that the fish don’t break them.

● Improvements would include changes to the pre-filter to facilitate cleaning and a way to bypass the bioconverter when treating with chems/meds toxic to the biomass.

● The pump should move at least 1000 gph into a 4 ft head. I’ve used a Rainbow Lifeguard Quiet One successfully for years.

● Use Teflon pipe joint compound on threads, not Teflon tape as it makes a better seal.

 

 

 

 

 

 

 

 

 

 

 

 

Tank, filter, bottom insulation, netting.

 

 

 

An optional up-and-over siphon-type standpipe with an external air gap may be used so that constant water additions may be made w/o overflowing the tank – see picture below of tank with insulation and "tent" (overflow on the right side).

 

 

 

Schematic (scanned from back of the AKCA Guide to Filters and Pre-filters) – UV optional

 

 

List of materials (assumes you purchase all items new and not on sale)

Item	Qty req’d	Price @ (approx)	Extension
Tank – 500 gallon show tank	1	$356	$356
Pump – 1000 to 1500 gph	1	110 to 250	110 to 250
32 gallon container	1	7.88	8
55 to 65* gal plastic barrel	1	0 to 25	0 to 25
OC foam bioconverter medium – 8"" thick – cut round	4 sq ft	18/sq ft	72
OC foam pre-filter medium – 4" thick	4 sq ft	10/sq ft	40
OC foam inlet filter – 4" thick	1 sq ft	10/sq ft	10
Matting in pre-filter – 2 ft x 2 ft x 1" thick	1	10	10
Heater – 250 watt	2 to 3	19	38 to 77
1.5" PVC bottom drain pipe – make	5.5 ft	2.98 (10 ft)	3
1.5" bulkhead fitting	1	7.30	8
1" bulkhead fitting	1	6.65	7
1" unions	2	2.69	6
1.5" Union	1	5.35	6
PVC pipe – ½"	20 ft	0.82 (10 ft)	2
PVC pipe – 1"	10 ft	1.98 (10 ft)	2
PVC pipe – 1.5"	5.5 ft	3 (10 ft)	3
PVC fittings – ½"	8	0.25	2
PVC fittings - 1"	10	0.75	8
PVC fittings – 1.5"	6	2	12
ABS fittings – 3" (PVC fittings are more expensive)	3	3	9
PVC glue – 8 oz	1	2.12	2
Tank netting – 7’x20’	7 ft x 7 ft	7.67	8
Pipe joint compound with Teflon –4 oz	1 can	4.32	4
Styrofoam 4 ft x 8 ft x 1" thick	2	5	10
Fiberglas insulation – 16" x 50 ft	1 roll	25	25
6 mil black polyethylene sheeting	10 ft x 25 ft	11.97	12
Duct tape - roll	1	3.47	4
¼ " poly rope – 50 ft	1	4.87	5
Silicone glue – 2.8 oz	1 tube	3.47	4
1 mil clear polyethylene sheeting	10’ x 20’	2.79	3
Optional – 25 watt UV light and fittings	1	200	200 (optional)
Optional –air pump and air stone(s)	1	25	25 (optional)
Total			$789 to $993 plus options

It is very difficult to explain all the nuances of these systems in one article. Please feel free to contact me with questions or comments. Spike Cover, 949-855-2371 (9A to 9P Pacific Time), scover@pacbell.net.

* Sometimes soft drink bottlers will have plastic barrels that can be purchased cheaply or are sometimes even given away. I got mine from Coke. Note: they do not weather well and need protection from the sun. An opaque tarp and/or paint can work.

About the author:

Retired mechanical engineer and entrepreneur who has kept fish virtually all his life. Has been serious about koi for seven years and is currently Program Director for the AKCA’s Koi Health Advisor program.