Well I dont have a phosphate tester kit, i will get one though. I do a 20% change a week. I have two powerheads and a pump from my sump. what macro algae product is good? I have a half live sand half crushed coral. Nitrate levek is 0 and the only parts of the tank which have the rusty algae are where light directly hits.Raptor said:Not long, it would be expensive food. Have you checked the phosphate levels? or nitrate? More flow,and clean water (Waterchanges) will take care of that. You can add a sump, and fill it with macro algae it will eat alot of the waste. I use a cpr hang on fuge, so i dont have to light up my sump. You can lessen the light time as well. I bet it is high phosphate/ silicate. What kild of substrate did ya use?