Im planning on switching out my live rock becuse I haven't been able to shake this hair algae. Despite weekly 20-30% water changes, GFO reactor, active skimmer, chaeto, reduced feeding, huge clean up crew, and reduced photoperiod. I destroyed the hair algae with algae fx but its creeping back. If you were to measure my nitrates and phosphates they would read close to zero (hanna checker, salifert, api confirmed). Water is rodi with 0tds. There are two clownfish and a mandarin in my 40 breeder with 20 sump. Was thinking about switching out my live rock with synthetic reef rock i.e., "real reef rock". My live rock leaching nutrients is only thing i can think of that might be fueling the growth. What are your thoughts on the synthetic "real reef rock"?