How many KOI?

[belairguy]

How many KOI fish can successfully co-habitate in a small pond? It's approximately 5 feet long by 3 feet wide, by apx 2 feet deep, with a continuous waterfall on a pump. Currently there's one 12-inch KOI and 10 5-inch small KOIs (small ones may be gold fish). It's in a warm climate at a home and I feed once per day. I wonder if the pond can sustain a couple more 12 inch KOIs. I'm new to this, at a new location. I wonder about the pond capacity for more large KOI and whether more large ones would get along with each other. Currently the environment looks stable with the big one getting along with all of the small ones.

 

[Sharpchick]

You calculate pond volume in gallons by multiplying the length times width times depth times 7.5.

So on the measurements you gave, your pond is approximately 225 gallons.

There are many factors to take into consideration to determine whether koi are appropriate for any given pond, including the dimensions and shape of the pond, filtration system capacity and operation, water quality, whether there are plants, etc.
Most domestic koi can reach 12 to 15 inches in length. Japanese koi usually get much bigger - 22 to 26 inches in length.

The general rule of thumb for water volume requirements for koi in ponds solely based upon gallons of water are 100 gallons per koi. For goldfish, commons, comets and shubunkins require 20 gallons per fish.

A full grown domestic koi is going to have swimming and turning problems in your pond.

And in my personal opinion, your pond is not large enough for the koi you have, and certainly not for two more 12 inch koi.

The way the water looks has absolutely nothing to do with whether it's a healthy environment.

What were your most recent water chemistry results, and when did you last test?

 

[jlk]

The multiplier depends on the shape of the pond. If its a perfect square or rectangle, use 7.5. If its circular, elliptical or oval, the multiplier is 6. So, if this pond is circular, it's capacity is only 280+/- gallons if it's entire depth is two feet. If it slopes from ground level down to a max depth of two feet, then it's capacity is considerably less.

I also disagree on 100g per koi. That is extremely small for a fish with such growth capacity. 500-1000g is more realistic. Likewise, 20g for a 12-18inch common goldfish is completely unrealistic as well. A better measurement for goldfish water capacity in pond setting would be based on 10g of water per inch of goldfish based on the modest assumption the goldfish will only reach 12inches.

 

[belairguy]

Reply

Thank you both... And a correction. The pond is an 8 feet x 6 feet oval, 3 feet deep. Other than the 12 inch koi, the others are all 4 inches. A neighbor offered another koi or two. Wouls you take another 1 or 2 12-inch guys? Would the big one like another big friend or two? Or would this be socially disruptive to them with more than one big one? Alsi given the corrected dimensions is that enough space for all. Its a strong waterfall pump and aerator.

 

[Matt68005]

I think that's pretty small for a bunch of big fish. Try fancy goldies I think for a small pond you know. Kois need a actual pond or lake. Not a small pond

 

[Sharpchick]

Thank you both... And a correction. The pond is an 8 feet x 6 feet oval, 3 feet deep. Other than the 12 inch koi, the others are all 4 inches. A neighbor offered another koi or two. Wouls you take another 1 or 2 12-inch guys? Would the big one like another big friend or two? Or would this be socially disruptive to them with more than one big one? Alsi given the corrected dimensions is that enough space for all. Its a strong waterfall pump and aerator.

No, I wouldn't put any more fish in the pond. And I don't think this particular pond is suitable for koi - any koi.