Urgent - Need Advice On Coldwater Filter

[fishnovice]

Basically, I had a large outdoor coldwater tank with very powerful filter. Tank was well insulated but owing to extreme weather conditions had to bring my fish indoors to save their lives and empty the tank. They would certainly have died if the tank froze and glass would probably have cracked too.Fish are now in 2large plastic crates, neither of which is big enough to use the original filter in so I'm doing 50% water changes 3 times a week.Kept the filter in one of the crates but not turned on. Will filter be OK if unused for a few weeks or will bacteria die? Could use the filter in my large tropical tank but will coldwater bacteria survive at 75degrees? Don't want to start major fish-in cycle when fish go back to their tank.

 

[black angel]

the bacteria would need the water flow over the sponges to keep alive so no it wont survive..you could have used it on the other tank as bacteria is bacteria, warm or cold tanks, doesnt matter. maybe wait until the fish need the filter again and just seed it from the tropical.