Fish and Chips With a Side of Water Lily

If you already have a pond or you're considering getting one you may be thinking fish. Whether you eat them or not is up to you (No, I'm not recommending it). Some of the more typical choices for ponds are Goldfish or Koi and each has its pros and cons. Keeping some fish in your pond is good for it. It helps to improve the water balance and decrease the number of snails and mosquitoes. Too many fish and you're asking for more work, a bigger pump and larger filter to keep up with the additional waste created.

Goldfish

They come in a wide range of colors, shapes and sizes. Goldfish with long bodies and a single tale such as comets and shubunkins can grow up to 12 inches (30 cm) long and tolerate water temperatures between 40 F (4 C) and 80 F (27 C). They can even live under ice if provided with an air hole to the surface. That being said, my parents have kept fish for years and left them in the pond to winter over. The pond is deep enough that it doesn't freeze solid. As far as far as I know they've never taken the time to drill any kind of hole in the ice.

The shorter variety of goldfish with double tails such as fantails and orandas, stay smaller but are less hardy. They prefer temperatures between 55 F and 75 F. Prices for goldfish vary but they don't cost much. Two or three goldfish can survive in a patio-size tub if protected from sudden temperature swings.

Koi

Koi can get huge. They can grow up to 2 feet (60cm) long and live for decades in suitable conditions. Prices range considerably depending on the size and quality of the individual fish. They can cost from just a few dollars for small fishies to thousands of dollars for mature fish. They like cool water, about 40 F (4 C) to 70 F (21 C) and will live well under ice with an air hole to release gases from the water. Koi eat plants and root around in the soil in pots and in the debris at the bottom of ponds. They produce lots of waste and demand plenty of oxygen in the water, requiring a large pond with a high-capacity pump and filter.

Some states and municipalities restrict the introduction of fish into ponds, even goldfish into home water gardens. Check with local authorities before stocking your pond, and never dump fish into a stream or other natural body of water or storm drain.