Las Vegas Koi Club Articles

This article was written for "Southern Nevada Trees & Turf" a landscape and landscape architect trade publication. 

As an active member of the Las Vegas Koi Club, I can tell you there is on going debate, discussion and passionate sides being drawn in the world of koi regarding the proper building of koi ponds vs. fish and garden ponds. Having attended many conferences, koi shows, seminars, wet labs and rescuing countless koi here in Las Vegas from “sick” ponds the need for education at the very beginning of a pond project has become critical both to the hobbyist and the professional installer.

Professional organizations are being formed to better assist the landscape industry in providing standards and education for the ever growing pond and water garden industry. One of these organizations is the International Professional Pond Contractors Association or IPPCA which was formed with the intent of bringing a standard of unity to the industry. I have personally spent time with the founders of the IPPCA and found them to be clearly focused on improving the standards of the industry while not endorsing any particular product or system. It is my hope that this organization and others like it can educate the landscape contractor and the consumer in the very different requirements of a koi pond.

There is room for every type of pond, filtration system, and method of construction in the industry if properly applied. With the availability of products such as the very successfully marketed AquaScape systems the “pond in a day” concept has flooded the industry. Whether it is built in a day or a week these ponds are lovely, functional and loved by the homeowner when first installed. If properly designed and built for koi they can be just as successful but there are basic differences that need to be addressed by you and the pond owner.

Once you put koi into a pond the whole “water world” changes. Koi are not goldfish; instead, they are related to the carp. If you look closely you can see the barbs or whiskers at the corner of their mouths. They are bottom feeders, like catfish and carp they grow at a rapid rate often doubling in size every year for the first three to five years. Suddenly that six inch koi is now 24 inches and still growing. It is commonly misunderstood that koi will only grow to the size of their container. Last year I was called to rescue four 18 inch koi that had spent nine years in less than 200 gallons of water. They were so large that they could not turn around or swim. Their fins had actually atrophied. Amazingly, after a few weeks in a large pond they learned to swim again.

Like all animal lovers, koi lovers are passionate about their pets. Whether an inexpensive “pond koi” or koi costing thousands of dollars and imported from Japan, they are all pets and the hobbyist spends a great deal of time and money to give them the best home as possible. Once the landscape feature pond is in place and the owner purchases their first koi the excitement leads to more fish, more food, more waste product, more algae more maintenance and now you have the pond disaster. Sadly many pond owners are given the wrong advice from the pond installer. The worst being “don’t feed your fish”. I have come across this time and time again here in Las Vegas. In an attempt to cut down on the waste in the pond and rid the water of ammonia or force the fish to eat the algae that has now turned the once clear water to pea soup, some believe that by not feeding the fish the water will magically clear returning the pond to the pristine past. The head of the koi should be the smallest width of the entire body. I have seen koi with heads the size of softballs and the body of the bat. Would we stop feeding our dogs to prevent them from littering the yard?

The number one rule in the world of koi keeping is you must have a bottom drain. The drain should be 4” pipe using curved pipe in order to keep angles at a minimum. In our desert climate the water needs to pump through the system a minimum of one time per hour, preferably 1 ½ to 2 times using high volume low pressure pumps. The system should never be shut off. Just a few short hours of the pumps being shut off will first kill the bacteria colonies in the filter then kill the fish with the decrease in oxygen.

A koi pond is not a swimming pool. These systems can be modified but they are designed for the pristine water environment of a pool with chemicals, not the natural water environment of fish. Mechanical filters separate the solids (fecal matter, dead algae, leaves, etc.) from the pond. The biological filter converts the ammonia from fish waste and biodegrading matter into nitrites and then further into nitrates. UV lights will help eliminate floating algae which causes the pea soup green water but they will not eliminate the attached forms of algae which establish on rocks, liner and water falls. Let your customer know that eventually those pretty rocks in the bottom of the pond will all soon turn the same color of green. It is best to not put the rocks in at all as they prevent the flow of debris to the bottom drain and become the host for anaerobic bacteria. Here is something to consider. A hobbyist lost his life last year after spending the day cleaning out the foul rotten egg smelling stuff in the bottom of his filter. The bacteria entered through a small cut on his hand and within 48 hours had attacked his heart. There have also been cases of the methane gas being released into the pond or the air causing fish die off and illness to the homeowner while cleaning the rocks in the bottom of filters or ponds. Keep in mind the initial odor of methane disappears after a few moments but the harmful gas is still present. Use gloves and caution.

If a customer insists upon adding koi to a pond the cost to accommodate those koi will far exceed the cost of housing a few goldfish or comets. Biofiltration for any type of fish pond is essential to a healthy system. The need for properly housing koi goes beyond the simple biofiltration garden pond systems that are easily installed by owners or landscape contractors. Dr. Erik Johnson, the leading “Koi Vet” in the industry said there are no improper filter systems but instead improperly maintained ponds. While controversial, the statement is true. The question is will the homeowner continue to maintain a pond if it requires hours each week plus a major shut down and draining every year. It has been my experience that after the initial thrill of the pond once the system starts to go down it is ignored until disaster results.

Before installing consider this rule for koi ponds. “One inch of fish per ten gallons of pond water will do well if adequately filtered, and small regular water changes are done”. To calculate the volume of water multiply the Width X Depth X Length and Divide it by the 231 (Cubic Inches in a Gallon) = Total Gallons.

If a homeowner can afford the cost of installing bottom drains, prefilters, settlement chambers and biofilters with a minimum of 3’ in depth they can have a successful koi pond with minimum maintenance. Providing the homeowner with a little knowledge of the different types of ponds and what they can expect can maintain your reputation and keep your customer happy years from now. Landscape contractors are not in the business of fish health and pond keeping but you are installing systems that does require this knowledge and on going care and maintenance. Encourage your clients join the Las Vegas Koi Club so they themselves can learn from the experience and mistakes of others who enjoy the hobby. Also, consider joining the Las Vegas Koi Club as a Professional Member to bring your knowledge to the club and share in ours.