It depends on how much work you want to do. The "standard" answer is 1,000
gallons for the first one, and 100 gallons for each of the additional ones.
The guys that like to maintain show quality fish have 1,000-1,200 gallons
per fish. In reality, the limiting factor is the amount of filtration you
have and the amount of work and money you want to put into the pond to
maintain the water quality. "Keep the water and the water will keep the
fish". In theory, with enough filtration, you could keep the current roster.
However, they WILL breed, and there will always be that fish that sits in
the retail tank and "calls to you" . . . to be safe, I'd find homes for half
of your current fish.

Lee

"Vic Tiongco" wrote in message
...
I have an 1800 gal pond how many 2 foot koi can fit in there? I have about
10 that are 1'6" koi, and have 10 less than 6"