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Build the Right Pond for your Customer
~ the First Time

By Tom Graham
T.C. Publishing, Inc.;Gardenside Publications
Reprinted with permission Pondkeeper Magazine

Note from Aqua Art: This article is directed to the new pond installation business, but the first-time do-it-yourselfer or anyone thinking of pond building and/or Koi keeping would surely benefit from it.

 In recent years we have (happily) seen an explosion in the interest in water features for the garden, particularly water gardens and Koi ponds. Hundreds of new pond construction companies have hung out a shingle, proclaiming themselves as experts in pond installation. The growth and success of this industry is great news for all of us who have invested our lives in bringing the joy of ponding to our customers and friends, but with all that growth, come problems as well.

Koi are finding their way into small, under-filtered water gardens, and pond keepers are experiencing devastating fish losses. A new segment of the pond business is even emerging, specializing in retro-fitting these ponds to accommodate the more demanding needs of Koi. Yes, Koi are a hot item, and they can herald an opportunity for a pond builder to expand his offerings to include more sophisticated upscale Koi ponds.

Koi are an adaptable species, and can survive in remarkably varied environments, thus they are well suited for life in a wide variety of garden ponds. It is not surprising then, that pond builders don't necessarily build ponds suitable for koi. The Koi often survive but they are at greater risk for predation, disease, stunting, sunburn and obesity. It is my feeling that if one is to build a pond with the intention of housing Koi, it ought to be designed for them to thrive, not just survive. This is not unlike building a salt-water community tank verses building a reef tank. A reef tank is a salt tank but the needs are different than a community tank, and the aquarium design reflects the specialized needs of reef dwellers.

No Sharp Objects
Koi are very high energy animals, which can be easily damaged in a pond that has sharp rocks below water level, or around the perimeter of the pond. Koi often rush around the pond when pushing each other around to get to food, when startled, or when dancing the mating dance. While beautiful rocks make a beautiful pond, the potential risk to the health of the Koi, in my mind, is not worth the trade off. The slightest abrasion on the side of a Koi creates a break in the defensive layers of slime coat, scales and skin. Once a break occurs, the bacteria that live in every pond have an easy shot at attacking our Koi's health, and fighting this kind of disease can be very difficult and expensive.

Even if the scrape is minor, it can relegate an expensive show Koi to un-showable status, a real heart breaker for Koi people who like to raise show quality Koi.

Feeding and Filtration
Koi, by their nature, eat all day long. They do not have stomachs to hold and digest food like most animals. They are grazers, so as a Koi keeper, we do our Koi a favor by feeding them as many times a day as possible. In tests on optimum growth, Andy Moo, of Andrews Koi International in Anaheim, California, found that Koi that are fed six times a day grew the fastest, without getting overweight or flabby. They held their color and conformation, and grew at an amazing rate. The notion that Koi don't need three meals a day as we humans do is simply nonsense. Koi will eat the bugs and algae in and around a pond, but most artificial ponds do not have enough to fill the needs of vigorous Koi growth. Visit any Koi breeder, with acres of mud ponds, teeming with natural food, and you will see them feeding their Koi extra Koi food many times a day.

The problem with this approach to Koi keeping is that some pond builders install systems with limited, easy to hide filtration systems that simply cannot process very much fish waste. Thus their customers call with complaints of green water, string algae, and dying Koi from bad water quality. Sadly, some pond builders are taught to tell their customers they are overfeeding their Koi, instead of admitting the possibility that the pond is not built to sustain more than a very modest collection of small Koi. The real sign of overfeeding is if there is still food floating after five minutes, or you see the white worm-like fish waste floating on the surface of the water, indicating that the food has rotted in the stomach of the Koi instead of being digested.

Imagine going into your local pet superstore, and asking the sales person for a larger cat box, because you are tired of cleaning out the old cat box so often. What would you say if the sales person told you that you were overfeeding your cat, and to cut back on his food instead? You would not accept that as a caring or reasonable solution, would you?

So how does this relate to Koi pond design? A pond designed to house koi needs to have a substantially larger filtration system than a water garden that will only have plants and a few goldfish. A Koi pond should be a large enough body of water so that chemical changes will be slower, and the fish waste will be diluted until the filter can process it. It should be deep (3 to 6 feet) so that water temperature changes will be slow and the fish have the exercise of swimming in the heavier deeper levels.

The best design for Koi is a self-cleaning pond design. This is a system where the bottom is smooth, and gently sloped to a bottom drain with an anti-vortex cover. The gently sloped bottom directs the settling debris and fish waste to the drain and out to the filter instead of building up on the bottom and decomposing. The anti-vortex cover stops the circular spinning (vortex) action caused when water goes down a pipe, like you see in a toilet. A vortex draws water from the top of the body of water, where an anti-vortex cover redirects the flow of the water along the bottom of the pond, sweeping the settling fish waste out of the pond to the filter. This is important for a number of reasons, not the least of which is that Koi sleep on the bottom of the pond at night. If there is rotting fish waste on the bottom, they will be much more prone to belly and fin infections.

Ponds can really take three to five years to fully mature. Many kinds of beneficial bacteria, protozoan and algae are very slow to develop and need to be left alone to multiply and take hold. A self cleaning pond never needs power washing, or the trauma of the "annual clean out," much to the dismay of some pond maintenance companies.

The second stage of a self cleaning pond is a particulate or mechanical filter of some kind. What is important is that the bottom drain be 3 inches or 4 inches in diameter and go directly to the particulate filter rather than to the pump. If it goes directly to the pump, the pump will puree the large chunks of debris into fine particles that are a lot harder to filter out. So the first stage should be gravity fed to a particulate filter.

The entire volume of the pond should go through the filter every hour, or two in larger ponds to be effective. The larger the pond, the larger the particulate filter must be to avoid frequent clogging and cleaning.

Once the water has passed through stage one, it can go to either the pump and on to stage two, or feed gravity style through the bio filter, then be pumped to the waterfall. Either way works fine.

Self cleaning ponds also include a skimmer but it is designed to take a minority of the total water flow, since its job is only to skim off the dust, oil and leaves that collect on the surface of the pond. The skimmer is hooked to the suction side of the pump or gravity fed to the particulate filter, again depending on the choice of components used.

Pond Depth
Depth, "ah yes," depth. So what's the big deal with pond depth? As a pond builder it is certainly easier to build a 24 inch deep pond than a 36 or 48 inch deep pond. The digging is tougher. There is more dirt to get rid of, more liner needed, and local regulations to be considered. So why bother? Just tell your customers that koi do fine in shallow ponds, you have built lots of them. Right?

Yes, Koi can survive in a shallow pond. But thrive? No. Koi are large bodied fish, whose native environments are lakes and rivers. In a shallow pond they are more vulnerable to predation from herons, raccoons, and other predators. Now if your client's Koi are just decorations, and expendable, loosing them may not matter. You know however, that in most cases, your clients become very attached to their Koi and once the pond has been wiped out by a heron or raccoon a few times, they will start asking about alternatives to the shallow "natural looking" pond design. Koi keepers have discovered that straight side walls, (and deep water) provides excellent protection against many predators. It also deters jumping out of the pond. As Koi race around a shallow pond with sloping sides, they can shoot along the bottom, up the sides and right out of the pond and find themselves grounded on dry land.

Deep water also provides a much more stable environment, which contributes to the long term health of the Koi as well. Deep water buffers rapid temperature changes, and allows Koi to go deep when the sun gets hot. Koi do get sun burned in harsh sunlight.

The depth also aids in the proper muscle development of Koi. The extra weight of deep water, and the effort required to swim to the bottom and back up, aids in the development of muscle tone, keeping the koi from becoming flabby and pot bellied. Koi are stronger and more vigorous in larger, deeper ponds.

I visited a very large shallow pond recently that was about ten years old, and some of the Koi had lived in the pond since it was built. These Koi were a real mess. First they were fat and flabby, and their pectoral fins were tiny in relationship to their distorted bodies. These fish needed to go to a fat farm to loose badly needed weight. Koi are elegant and powerful fish, so to see these in this state was really quite sad. If these fish were put directly into a deep pond, they would actually be at risk of having a heart attack, just like obese humans.

Koi that are well kept have good body shape and muscle tone, or "good conformation." Body conformation is recognized as a key ingredient to the visual appeal of Koi, as well being a primary ingredient in its valuation.

Talk with your clients about what they want - long term
So when you sit down with your clients be sure to do your best to determine what they are really looking for in a pond. If they are planning on keeping Koi, guide them to a design that is designed with the best interests of the Koi in mind. It can still be a beautiful pond, and still have water plants. It just needs to be built to accommodate the special extra requirements of Koi as well.

Remember - three or four Koi can survive in a small water garden, but most people don't stop at three or four. Those small 6 inch Koi that they start out with, will double in size in a year or two, and when they do, the waste they give off increases six-fold. A pond that works in its first year or two, could be in real trouble in year three if the filtration is not up to the increased load from the increased fish waste. Providing a pond that will work long term should be your real goal.

Selecting the right pump
Here is where you can actually save your customers some serious money. Many pond builders like the easy installation of a submerged pump. This is nice for the builder but expensive for the pond owner. Since these pumps need to run twenty-four hours a day to keep the bio filters alive, they can use up a substantial amount of electricity. There now are a number of pumps that look similar to swimming pool pumps but function quite differently. They pump at very low pressure but very high volumes, and use very little electricity. The difference can be hundreds of dollars a year in electric usage, plus they are designed to run far longer than most submersible pumps.

So here is my short list of the elements that should be included in a pond intended to house Koi.

Koi Pond Basics
Substantial Bio Filtration
Substantial Oxygenization
Straight sidewalls
Depth 3 feet plus
2000 gallons or better
Efficient 24-hour external pump
Once an hour turn over for particulate filtration
No sharp objects in or around the pond
Limit submerged shelves or rocks
Bottom drain

It is your responsibility to know the true Koi handling capabilities of the pond systems you are installing, and be sure to explain the possibilities and limitations to your customers up front, so they will have a positive pond keeping experience, not only this year, but for years to come.


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