How to move koi from 40F to 65F safely?

[SimonW]

Dear friends:

I am going to move my koi indoors this winter, and I may not be able to do it until the outside pond water temperature drops to like 40F: I have to wait for the bio-filters to establish for the indoor tanks.

So I will likely face the problem: How can I move koi safely from 40F to 65F?

I am afraid that it would be too fast if I put the koi in a plastic bag with some 40F pond water and then just let the bag floating on the surface of 65F tank water, or it is ok for koi?

Thank you for your advice!

[ademink]

You will need a bunch of rubbermaid/plastic tubs, aerators and ammonia binder. Bring the fish in and put them in the small holding tubs until the water comes up to room temperature. I normally find that this is overnight. You can then add the fish to the water.
Each tub will need an aerator and you will need to add the appropriate amount of ammonia binder.

I'm not sure how many fish you have but it may be easier to bring them inside and just use ammonia binder every 4 hours in the indoor tank until the filter matures.

[SimonW]

Hello Andrea:

Thank you so much for your advice!

Maybe I can do it one bigger koi a time, as I have very limited space in my garage.

The problem is that in the tiny Swedish market I have not yet discovered any store that sells the wonderful thing called ammonia-binder. So I wonder: Will a 50 cm koi survive in a barrel of 55 gallon barrel overnight without ammonia-binder? Of cause it will be aerated.

I have several 50 gallon barrels. So maybe I fill the barrels with the cold pond water at the same time as I move one koi to one barrel, and then I do water change very 4-5 hours. As the barrels are the same model the water will warm up at the same pace.

By the way my pond water has a pH of 7.0, so ammonia may mostly be ammonium-ion.

[ademink]

I would say yes to surviving overnight. Prior to understanding the use of binder, I did this same process without it. Binder is "ideal" but not mandatory. If you can do one 25% water change, that would be a great safeguard (just make sure it is water of the same existing temperature as the barrel water).

You could also bring everyone into the tank at one time and keep the ammonia under control by doing water changes. I have also done this. It was something else....50% water changes every single day for 6 weeks. WHEW. lol

[SimonW]

"It was something else....50% water changes every single day for 6 weeks. WHEW. lol"

You did that?! I am impressed really, and I admire you!

Thanks so much again för your great information. I feel much really confident now.

[ademink]

I definitely learned a lot through that insane experience! We had a polar vortex here in the US and had subzero temperatures. Fish were literally freezing to death in the pond. Necessity was definitely my teacher. I’m glad that my experience is helpful to you. :-) Please feel free to ask any other questions that might be helpful.

[SimonW]

Update:

I have succeeded in moving the koi from 40F to 65F.

First I bring in the koi with 10g cold pond water (40F) and let them be in the 65F garage for 5 hours. The temperature went up to 50-55F. Then I put the koi in plastic bags and let them float in the destination tank for 40 min. It worked fine for all my koi. Took 2 days. Aeration during the entire process.

[ademink]

Happy to hear the transition went well!

[htgoldfish]

If your outdoor pond is bigger than the indoor one, I think it is easier to just pump the cold outdoor pond water to fill the indoor pond. That way, you can move the koi directly from outdoor to indoor without the floating plastic bags.