Hi, My name is James. I have a 75 gallon reef tank been up for about 3 years. I'm struggling to keep zoanthids. I have some hammer corals and rose bubble tips, frog spawn but I can't achieve full extension from any of them. I found that part of my problem is my tank build, a 75gal (All in one) SeaClear System II. I water change every week and have only 3 fish. Water testing is difficult as I can only afford low end test equipment. May I have some good suggestions please?