Koi Basics 1

Nishikigoi Care - Just the Basics It can be overwhelming for those new to the hobby when the amount and level of knowledge necessary to be truly competent in the care of koi starts to become apparent. What I want to do here is break down a lot of information into a few easy to understand guidelines for those of us who are beginning or who have experience with watergardens or smaller water features. First, let’s define what the possibilities are and then what it takes to get there. We all know that koi are mutated carp and as such are very hardy animals. It is possible to keep koi for a few years in an 18” deep watergarden system which just circulates the water but has no real bioreactor. The results will be a 12-18” koi with less than ideal color and increasing health problems. You can anticipate increasing problems with water quality as the stocking levels quickly overload what bioconversion is present. This is what many people believe to be the standard in the hobby. If you are dealing with only big box pet store koi which you consider to be easily replaced that may be good enough. However, a watergarden system as described cannot begin to get koi to what their genetics are capable of producing. Here are realistic goals assuming proper mechanical systems and good husbandry practices. 24”-30” length 6-20 pounds Life spans approaching 20 years or more As you can see you don’t have to settle for disposable low grade koi as long as you employ these few basics. 1 - VOLUME PER KOI 50 to 125 gallons per lb of fish Koi are large animals capable of producing a lot of waste. Don’t fool yourself into thinking that you can have ten koi in 1000 gallons. After a few years of growth, no filter / bioreactor system will be able to maintain a stable environment. length............weight 12”...................2/3 to 1.2 lbs 24”...................6 1/3 to 9 1/4 lbs 30”...................12 3/4 to 17 2/3 lbs 2 - POND DESIGN 6-8’ DEEP - Depth provides a more stable temperature range, helps koi stay out of direct sunlight and regulate their internal temperature. Deeper water also helps koi avoid predators and gives more exercise to koi than shallow water which leads to more mass. Check local codes for depth limitation or fencing requirements. Liner ponds may have fewer limitations as they are sometimes considered temporary structures. Steep sides with 10 to 15 degree bowl. Steep sides prevent predators from wading in and fishing for your koi. They also allow debris to settle within reach of the bottom drains. The bowl shape will allow winter ice to move up as it expands reducing pressure on the sides. Odd shapes lead to stagnant areas. They may look more interesting but odd shapes and deep corners lead to stagnant zones where flow is reduced and debris collects which increases your workload. Bottom drains do your maintenance for you. There are very few absolute truths in this hobby but this is one you can count on! A pond without bottom drains will require that you remove debris manually with a vacuum system on a regular basis. There are many products out there which claim to remove sludge but none is perfect. The accumulation of waste in your pond will lead to an increase in parasites, decreased growth, and the release of toxins like hydrogen sulfide gas (rotten egg smell from bubbles released when debris/sludge is disturbed). Bottom drains remove waste and debris to you filter system where they can easily be removed from a settling chamber or from some form of mechanical filter media. It all come down to this. You can spend time cleaning you pond or you can put in a little time and money into the construction of your pond and greatly reduce your workload. Turnover Rate - This is the time required to pass all of the water in your pond through the filter system. The quicker you can make this happen the better. There are many different rates published, but all are affected by the type of equipment used, stocking levels, and maintenance intervals. Here are a few numbers to get you in the game. <5000 gal - once per hour >5000 gal <15000 gal - once per 1.5 to 2 hours >15000 gal once per 2 to 3 hours 3 - REGULAR WATER CHANGES There is not another procedure, treatment, chemical or magic potion that will be as beneficial to your koi as the weekly removal of 10% of the old water and replacing it with fresh water. Doing water changes removes Nitrate - This nontoxic end product of your bioreactor will encourage algae blooms if allowed to build up. Removing it naturally in this way lessens the need for chemical treatments to control algae. These products can be dangerous as they use up oxygen. Dissolved organic carbons (DOC’s) - These are dissolved waste products from your koi and from the break down of debris in you pond. Buildup of DOC’s is present if there are a lot of bubbles or foam on the surface around an aeration source. Again, now you don’t have to add a different chemical to control foam. Doing water changes replaces - Minerals - Your koi use the water around them as a source of minerals for the bodies. Your bioreactor also uses calcium carbonate in the processing of ammonia. Adding fresh water will help your bioreactor to function at a higher level. You must treat tap water. Call your water supplier to find out which of the following is reaching you pond. Chlorine - Treat chlorine with a product like Vanish. It only removes chlorine making it more economical. Chloramine - If you live at the end of a supply line it is likely that chloramine is present in your water. It is a combination of chlorine and ammonia, which makes it longer lasting than straight chlorine. If you use a product like Vanish you will be releasing extra ammonia into your system. Use a full water treatment like Ultimate. It removes chlorine, ammonia, and heavy metals like copper. References- Associated Koi Clubs of America Koi Health Advisor (KHA) course material Advanced Koi Health, Nick Saint-Erne DVM Koi Health, Erik Johnson DVM Koi Pond Design and Construction, Bert Ballou Koi Pond Filter Design and Construction, AKCA Koi USA Magazine, Water Quality by Ray Jordan