My tank is a 46 gallon bow front. I use water that has been ran through a water purifier. I have no substrate, just a lot of beautiful green algae and coralline algae covering the bottom. Occupants are live rock, green mushrooms (just a few on 1 rock), zenia ( on 2 rocks), pulsating zenia, 1 clam, 1 bubble coral, 1 orange tree sponge, 1 long tentacle anemome, 1 saddleback carpet anemome, 1 bird's nest coral frag, 1 toadstool, 1 colt coral, 2 tank raised perculas, 2 black perculas, 1 six line wrasse, 1 scooter blenny. I know it seems like a lot when I write it down, but I have really good filtration. I have one canister filter, 2 large filters with bio wheels (Im not sure what brand, but my husband knows:>) !!!) Also, added a power head this January to incorporate more of a current around bottom of tank. The ammonia is 0. The nitrites are 0. The nitrates are 40 and the ph is 8.0 to 8.2. Salinity is 1.023. I'm not sure exactly what the numbers are on the general hardness and carbonate hardness. I just know that they are reading in the good to excellent range. (I'm at work and can't remember the numbers at the moment!) My husband asks me all the time am I testing my water. Therefore, it gets tested on a regular basis. I did a 50% water change on Jan.8th. I did slow down feeding the corals this week and it does seem to be doing better. I mean just a week ago, I found a frag that had split from the main zenia head on the bottom of my tank and it is starting to sprout and grow. Thanks for getting back with me. Oh, the tank has been up and running for a year.