You need to put that rock in the tank. it will cycle and HELP your tank cycle too. It will have die off which will produce ammonia. You need that in your other tank. Unless you still have fish in it. Then I'm not so sure how to proceed. LOL
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.