How Many Pond Fish?

How Many Pond Fish?

Pond owners commonly ask, “How many fish can I have in my pond?”

The answer is, “It depends.”

Three factors influence the “fish capacity” of your garden pond:

• – The type and size fish you want to keep.
• – The type of pond filtration.
• – The level of maintenance the pond receives.

Koi generally eat more and grow faster than goldfish. The larger the fish, the more food consumed and consequently the more waste produced. The amount of food entering the pond is the single most important factor in determining water quality, and that, in turn, determines how many fish the pond can sustain.

A “natural” pond with little or no filtration will obviously be able to handle fewer fish than a pond with the latest advanced filtration. Does the pond have good water circulation? If so, it will accommodate more fish than one without water movement. Is the pond in the sun most of the day? If so, it is likely to be warmer, and will therefore hold less oxygen, which limits the number of fish that can live in it.

Are you conscientious about water changes and filter maintenance? The better you maintain the pond, the more fish you can keep. Do you want to grow and maintain show-quality koi, or do you just want to have a few goldfish to make the pond interesting? For the highest quality fish, keep the stocking level to a minimum to give each fish plenty of room to grow and thrive. Also remember that koi grow quickly.

With all of this in mind, here are some reasonable starting points for stocking a pond with basic filtration.

• – Small fish – 3-6”
• – 10 koi per 1000 gal
• – 15 goldfish per 1000 gal
• – Medium fish – 6-12”
• – 5 koi per 1000 gal
• – 10 goldfish per 1000 gal
• – Large fish – 12-24”
• – 1 koi per 1000 gal
• – 3 goldfish per 1000 gal

Ponds in light shade with state-of-the-art filtration and regular maintenance can typically accommodate 30 percent more fish.