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How long could a koi and goldfish stay in a 20G long tank?

2K views 2 replies 3 participants last post by  thekoimaiden 
#1 ·
Back in like April I think when my other large koi went back into the pond from overwintering, I got a small koi and golfish and started quarantining them in the tank. It's been about 5 months now then and I guess they're fine but I don't want to put them out in the pond now with it getting colder since I never got to make a larger deep pond like I wanted, so they'll have to stay in there for a while longer. I don't have a filter or anything on it, just a glass cover and it's on a window ledge so it gets some sun, and I have anacharis in there and will put some hyacinths in there and hope they aren't eaten to shreds like the last bunch I put in was, and I do water changes every few days. Nitrate is low, last I checked, 10ppm I think it was, whatever the lowest marker was other than 0, but I don't have an ammonia test right now and was worried it might build up with no filter. LIke I said, theyre small, only about 3inches long each, just thinking since I couldn't get them a pond to stay in I'll make their tank nicer with some actual substrate(just have a spattering of ammonia absorbing gravel things and a pile of rocks in the corner) and maybe rig up a light for them.
 
#2 ·
Where do you live? Generally goldfish can survive very low temperatures as long as there's a hole melted in the pond for O2 and if there's not decomposing weeds under the ice.

But anyway as long as the goldfish and koi are both very young (small), they should be okay till the end of winter but after that i would advise not keeping them in the 22 any longer because Kois grow HUGE.

I would also strongly advise a powerful filter if you are keeping them in that tank
 
#3 ·
I have done something very similar to what you are doing. Except my tank was 50 us gal and there were 5 koi and 2 goldfish. I needed two very powerful filters to keep the waste down. I would not add the fish to the pond right now. I also made that mistake and added small koi to my pond late in the season; I never saw them again. My advice is to get a bubble stone to increase the O2 levels and get a filter. Goldfish and koi are very dirty fish and need heavy filtration. Hope this helps even though I'm a little late!! Happy fishkeeping!
 
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