Yes the Bio Spira will help cycle the tank. I've never attempted to use Bio Spira mid-cycle so I'm not sure how and when to add it. But if it were me, I would wait for the ammonia level to read 1, put in the fish and bio-Spira. Then monitor the levels every few hours to make sure the ammonia level doesn't get too high. but make sure you start with hardy fish. Nothing like Rams.