Wintering Over Koi in A Show Tank and Other Tidbits About Show Tanks You Might Find Helpful

by Ray Washington
Pearls of Paradise
reprint from Koi USA

Many hobbyists like to move their Koi indoors during the winter in order to reduce stress and continue the growing season. Many hobby ts use their show tanks for this purpose placing the tanks in their garage or basement.

Most basements have bare concrete floors. Placing the tank directly on the bare concrete inhibits the tank's ability to retain heat as the concrete will retain a temperature of 55F or less, drawing heat out of the tank. To avoid this, place insulation on the concrete directly under the tank. Any foam insulation of 3/4" thickness will work, or you can use a bubble-type insulation known as Reflecix, like we do. It is available at most hardware stores and has a very good "R" value. You can also insulate the outside of the tank by wrapping a long piece of Reflecix around the tank, followed by a single layer of vinyl, lacing it shut with rope or shock cord. This holds the insulation tight against the tank. This type of bubble insulation is easily rolled into a tube for storage.

HEATING THE SHOW TANK
There are two main ways to heat your show tank. You can use a 1.4-kilowatt, inline spa heater located on the out-flow side of your centrifugal pump, or use numerous aquarium heaters. We do not recommend piping in a side line off your home water heater it is too hard to regulate the tank's temperature. It may necessitate consistent dechlorination of the water, and may require the plumbing of an overflow line from the tank. If you use aquarium heaters just be sure that the heaters are placed inside the filter to prevent them from getting broken by the active Koi.

As a benefit, since you will be heating the water, you can place several hyacinths in the filter tub, as long as a grow light is used. Hyacinth roots must be kept in water of 60 F, or above, to get them to survive the winter, and they require a minimum of light. They won't grow through the winter, but they will survive, giving you starts for next spring.

FILTERING THE SHOW TANK
Filtering the show tank can be accomplished using one or more 55 gallon barrel filters. If you use mesh for the filter media, do not wrap it tightly inside the barrel. Wrap it loosely to allow increased water flow and surface area for bacterial growth. The biggest mistake in using mesh as a filter media is wrapping it tightly inside the barrel. This cuts down the surface area for the bacteria to grow and necessitates frequent cleaning, destroying the bacteria. Remember though, do not pump more than 5 gallons per minute through a 55 gallon barrel filter any faster and the water moves through too fast for the bacteria to feed off the ammonia, nitrates, etc. resulting in only mechanical filtration of the water.

COVERING THE TANK Tank net covers are widely available and recommended when keeping fish inside. We use a black colored, delta weave, polyester net to prevent the fish from jumping out. The delta weave prevents catching scales, and has enough stretch to allow even the largest Koi to "hit" the net without damaging the net orm pulling it off The net is made with a vinyl sleeve which "grabs" the vinyl of the tank, and a shock cord is provided inside the sleeve to tighten the net down even further. Black netting is used to increase your ability to view your fish, as trying to focus through a white or light- colored net creates a vertigo effect! Falling into your tank is not recommended, so if you buy your own net get a black one! STARTING UP THE SYSTEM
When starting the system up,remember that the filter is void of bacteria and the Koi will have to gradually be brought up to the optimum eating temperature. To help "set" the system, the following steps should be followed:

MISCELLANEOUS HELPFUL HINTS
Many of the following hints fall under too many categories to list them all separately, so we have thrown them all in together.