I want to start a new tank quickly by getting some cycled media or a pre-seeded filter. But if I do this and then fill the new tank w/ tap water, won't I be killing the BB on the filter? How does this work?
You will have the filter switched off when filling up the new tank, dose the tank with prime dechlorinator as you fill it up, prime neutralizes the chlorine in seconds. By the time you are done filling up the tank and then start the filter you are good to go
Just make sure that the filter media stays wet and not sitting with moving water for a long time.
When i started my 75g,i set up and filled the tank + prime then went to my LFS got seeded filter pad and added it to my HoB and Canister and then started the filters.