Ok, here goes. How long can a koi live in a an aquarium? That is if he or she can live in an aquarium? The reason I ask is when I bought my first gold fish I saw the koi about 4 inches that looked like he had gold dust sprinkled all over him. I knew koi live in ponds but I sure wished I could have bought him. How big would he get in a 30 gal. all by himself, or would he be badly stunted?

You made the right decision by not getting the koi. For one, koi grow way too fast too be kept in small aquariums. In my estimation a full grown koi (28"+) will produce as much waste as 25-50 goldfish if not more. Two, koi will not do well if kept alone. While most goldies can do fine by themselves koi definately need other fish around too be well adjusted.
To answer your question, I think you could get away with two 4" koi in a 30 gallon for a maximum of 6-8 months. Beyond that you will no doubt be stunting their future growth and water quality will be a problem. I would only buy koi if they had a suitable pond too go into after their quarantine. Overall koi are pond fish and are not meant too be kept in aquariums for any extended amount of time.

*whistles innocently*

Firstly, what you saw was likely a kin variety of one of the other types of koi. what were the main colors?


Secondly, I rescued three baby koi out of the feeder goldfish tank.

I do weekly 40% water changes, have two filters running, and spend most of my day observing my fish for any signs of stress.

They are currently in a ten gallon tank. Two of them grew from 2 inches to 4 in the last month, and my previously 1 inch fish is now 2 1/2 inches or so.

They're getting moved to a 20 gallon water garden tub that has a filter designed for a 50 gallon tank for the winter (the current home of my goldfish), and the goldies will be moved to a 30 gallon tub. After that, money is being saved up for one of those giant rubbermaid trough thingies to go in my grandparent's backyard. My koi should be in that by march, when the weather starts warming.


If that koi you saw was in with other koi, being sold as a koi, leave it.

If it was in with the feeder goldfish, go nab it, raise it in that thirty with a goldfish (they'll get along fine) until he's about 6 or 7 inches long, and then give him to someone at your local koi club. That way he gets to live and prosper, you get to have a wonderful fish, and you will know that he will be well taken care of.

Im not sure about koi ... but
i think the rule is
100gal=1 koi

That is the usual rule, but you can get away with a lot while they're young. But they do need ponds and lots of water.

Im new to koi,im plaing in getting 1 next summer