Backyard Aquaponics
A place to discuss aquaponics

So I am working to expand my indoor system and I got a really good deal on a 125 gallon (475 liter) tank. My wife and I decided we would like to stock koi in it. How many koi do you think I could put in there? I know they can grow to be quite large, I am also trying to figure out if there are other types of compatible fish that I could also have in there that won't try to eat each other. Since this is indoors I don't have to worry about water temps much as it will be a steady 68F (20C) year around.

Koi need big ponds. Bigger than than 125 gallons. Maby try some Sarasa Comet http://www.liveaquaria.com/product/prod ... catid=1041

It really depends on the size koi you are planning on getting. I know with goldfish, they will grow as large as the space, feed and population allow. A few goldfish in a small tank won't get all that big, 1000's of goldfish in a pond won't get all that big. a few goldfish in a pond with ample feed and filtration can get huge!!!!! Question is what are your goals with the koi? If you want to grow large koi, an aquarium is probably not gonna do it.

Um, the main goal of the koi is my wife doesn't want to grow fish to eat in the house, when I have a system outside she doesn't care but she thinks of these as pets.

So in other words I can just drop in as many as I want and they will grow to a comfortable size, within reason at least. I was thinking earlier that having 15-20 of them would be nice in there but that may get too crowded with how big they may get.