i have three tanks and one of them had a cycle crash due to medication which was no problem as i was moving the fish to a bigger tank and had a spare tank anyway now i’m trying to recycle the tank and have put the filter in an already cycled tank and i’m wondering how long it will take for the filter to build up enough BB so it can go back in the other tank again with some fish sorry if this is confusing i didn’t really know how to word it