I am still battling what I was told is cyano algae but I don't even know for sure what it is. It is to the point now where I have to sweep the tank at least once a week because it comes back so quickly... changing water 30+ gal. a week (210 gal. system) and lost another fish last week. I use RO/DI water and the parameters are ammonia 0/nitrite 0/nitrate 0/phosphate 0 (JUST tested). I am seriously considering ripping the entire system apart and starting from scratch again. What are your thoughts on completely restarting the entire system? I am down to my last two clowns and they appear to be healthy so I would only start over if I lost these last two fish. I cannot even keep a cleanup crew alive anymore, I spent 50 bucks on hermits/snails and I only have 2 or 3 hermits alive now out of the whole crew. I just dosed the tank with AlgaeFix today and hope that works. Is it the lights? I just bought new lights about 1 1/2 months ago (Sunpaq 130W dual 6500k) my halides have been turned off since I got these lights because I cannot keep any coral alive. I did put a cheap light bought from lowes in my sump though.... turned off today and am leaving it off even though that will kill my cheato which I'm not really worried about because at this point I'm just sick of the entire system. Suggestions greatly appreciated!!