Keeping Koi Healthy

There really isn't a trick to keeping your Koi healthy. In general, Koi tend to be healthy, until we subject them to conditions that are outside their ability to adapt. Give them a good home and good food, and they can out-live you! In spite of what you may have heard, Koi have a pretty good immune system. They live in a fluid environment where they are in constant contact with potential diseases. As long as their immune system is not compromised, they will successfully fend off most every disease that comes their way.

The Key to Koi health is WATER QUALITY. Take care of the water; the water will take care of the Koi. Conditions that favor Koi, do not favor disease-causing bacteria, or bacteria-carrying parasites. But, should water quality shift towards favoring either parasites or bacteria, your Koi will be in trouble! Another primary Key to Koi health is to avoid over-stocking the pond. In some ways, this can be harder for many people than the water quality issue. But this *is* one area that you absolutely *must* develop some discipline!

Look at the word, "Disease." It breaks down like this: "Dis - Ease." And we want our Koi to always be "At - Ease," or, relaxed and happy!

Bacteria are always present in the water. You cannot simply sterilize the pond and keep it that way! Your Koi can defend itself under most circumstances from these bacteria. But, let the ammonia levels creep up, or any of the other water chemistry factors, and the Koi starts getting stressed and stress does tend to suppress the immune system.

Water borne bacteria need a way into the Koi, in order to make it sick. The Koi's first line of defense is its slime coat. A reduction of the slime coat to a fish is just like a break in the skin to humans, it's an open door for infection. The primary method of entry for bacterial invaders is with the help of an accomplice! The usual suspects are Flukes, Chilodinella, Costia, Epistylis, Ich, Lernea, and Argulus. All but the last two are microscopic, so a microscope would be a good tool for most every Koi keeper to have, or at least, have access to.

There are treatments available for all of the parasites listed above. But continual use of the treatments can be dangerous for the Koi and an indication that something is seriously wrong with the pond, or rather, the way it's being kept.

Keeping the pond clean will go a very long way towards minimizing health problems. In fact, some of the parasites require a dirty pond in order to be present in sufficient numbers to pose a threat to the Koi!

The same applies to the biofilter, as well as settlement areas or sumps, if they are part of the design. Any "dead spot" in the system is a potential problem. A thoughtfully placed airlift, or air stone will eliminate "dead spots." Water returns to the pond should be on the opposite side from intakes to the filter system. You should design the pond to not only circulate the water through the filter system, but to also literally "turn over" the pond, top to bottom.

A UV system will not only help keep the water clear enough to see that the fish are healthy; it can help reduce the waterborne bacteria, *if* the right size UV is chosen and the proper flow rate is maintained. Most of the time, the UV does little more than kill off the single-cell, suspended algae that turns water green. One product that will help tremendously with keeping the numbers of disease-causing bacteria to an acceptable level is LymnoZyme. Since the "friendly," or benign bacteria in Lymnozyme are added to the pond in a greater concentration than the existing resident bacterial population, the LymnoZyme bacteria will dominate the water, actually eating the Aeromonas and Pseudomonas bacteria out of house and home. And those two bacteria are the ones that kill more Koi than any other disease! (Unless you count over-crowding, over-feeding, not-quarantining, or "Koi keepers" as diseases, that is.)

But you'll find that you *can* maintain a "clear water" pond, without a UV. Many have done so, for years. For others, a UV seems to be the only way to beat back the "greenies."

Never, EVER, put newly acquired Koi in with your resident population without a proper quarantine! No matter WHERE you get them! The notion of buying "pre-quarantined" Koi is a sheer fantasy. An article on Quarantine will be posted in the future.

To return to the basics, learn to take care of the water and the water will take care of the Koi. You should endeavor to become your own "water quality expert." Water quality problems are usually the root cause of disease problems. And water quality problems seldom crop up overnight. By doing routine water parameter checks, you will be able to head off a small problem before it has a chance of becoming a BIG one. More on water quality will be covered in an up-coming article.

You can become your own fish Vet, or at least, a pretty good field medic! Dr. Erik Johnson's book, "Koi Heath and Disease" will provide you with a firm foundation in Koi health. His video will make some of the procedures and processes easier to understand, it is an *excellent* companion to the book.

A new resource can be found on the AKCA's web site. The organization's Koi Health Advisor program has finally gotten off the ground. They are *not* keeping the course materials to themselves, either! It was decided to post the course modules on the AKCA web site, so anyone and everyone can benefit from them. Dr. Sandy Yosha has written a comprehensive module on fish health. There are other modules on water quality, and all aspects of Koi keeping. These modules can all be downloaded and are in the pdf file format. There's a link provided, if you don't have the free reader required to view pdf files.

See the "Links" page to find the web sites mentioned above.

I will not be going into very much detail on the treatment of Koi health problems. I'd much rather you read, study, and *learn* directly from the sources I'll provide. Some of the treatments can be dangerous to your fish; some even pose a risk to *you*. This is one area that you really should AVOID "second-hand" advice.

I will probably write a bit on some of my preferred treatments, and some "treatment philosophy," as well. Most of the time, you'll be directed to what I consider a *trusted resource* for details on the actual treatments themselves.

It is hoped that you will learn to prevent problems, rather than spend much time treating them. To do otherwise would take all the fun out of the hobby.

Mike S

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