if you are talking about Cycle or similar product it is liquid bacteria and I have had good results with it. it helped keep my water parameters at non deadly levels during initial cycle of my tank and after my tank emergeny this morning ( floor is wet, sloosh, sloosh) I added some to th elaoner tank until I can get a new one in a few weeks. Oh yeah, welcome to our forum. there are great knowledgable people here that are very helpful. they have tough me alot in a short period of time B)