| Difference of opinion here, but I kept the fish in for the cycle as long as you treat with Prime daily, but not water changes. Prime doesnt have to be administered with a water change, and it will still detox any toxic ammonia and nitrites. You would have to pour it in to overdose the stuff, so its pretty safe. I would expect the cycle to be relatively quick if there is media from an established tank though.
Water changes is probably the best thing for keeping fish, but my danios survived just fine in my 20g with only weekly water changes (but daily Prime treatments) during the cycle. |