One more question, how long have you had the anemone?
Three things catch my attention that no one else mentioned.
1. Was the tank set up with dry rock? If so they typically take much longer to become established and anemones do not do well in tanks that are now well established?
2. Anemones love light. I would increase the strength and number of hours you light your tank slowly. Have you taken any par readings on your tank if not try to barrow or rent a par meter to see where your at. BRS rents them.
3. Nitrate is a food source for anemones. I don’t know what Chemiclean does to water chemistry. If your nitrates recently dropped due to the changes you did, that combined with low light levels could be the reason it is unhappy. It your doing anything to reduce nitrates I would cut back until you get nitrates to at least 10. If you don’t have SPS or other sensitive corals I would let it climb higher. BTA anemones are very happy in nitrate levels, as high as 150 in my experience. BTA anemone farmers feed them nitrate added directly to the water column.
