Good information. When I cycle my tank with shrimp I leave the shrimp until all readings except NO3
goes to 0 then I wait a few days to be sure then I add my CUC and a fish. At that time if there is any shrimp left I just push it into the sand. I run a DSB
....If you don't use sand, remove remaining shrimp then. That way you will have an ammonia source till then. The ammonia does not disappear it is just being consumed as fast as it is being made. That is when you have enough bacteria for each source of the cycle. Ammonia, nitrite,nitrate. My DSB
takes the nitrate and reduces it to Nitrogen which bubbles off into the air.