I dont know what is wrong with your tank but I can tell you what fixed mine. I was having a lot of the same problems, I tried what everyone said to try (feed less, less light , more water changes, phos gaurd and better protien skimmers) and nothing worked then I bought 12 cherry stone clams (cleaner clams) at the super market and it fixed my problems. they cost me 4.00 for all of them. They are filter feeders and will eat the stuff that is messing up your tank. You may want to try them they are a lot cheaper and easier. try letting nature fix the problems. good luck