The tank has had regular water changes since it was set up. Its a TBS tank, so when the ammonia or nitrates were\are even barely detectable, he did a water change. I cant tell you how many he did, the most recent one was on Sunday morning. I dont know what the exact parameters are, and I dont have time to check. Hubby tested the water while I was out of the house on Saturday, and all he said was that everything was fine. He is out of town, so I cant ask him what the numbers were. He got the nem from a local reefer. When he got to her house to pick it up, she didnt have it off of the rock yet, so she removed him in a hurry. I dont know how she removed it, or what the nem was like when he got to her house because I wasnt there.