The filters in a R/O unit should be change every 6 months or so, with the exception of the membrane, they typically last 1.6 to 2 yrs. Test your R/O water. Luna _________ 9YR OLD 90G 30G w/d Mag18 150G skimmer 692w MH,yel&kole tang,foxface,midas&convict blenny,B&G chromies,Blk/yel fin chromie blackcap,nemo,neon goby,6line; Blastomussa Merleti,Acan ,BUBBLE,Torch,LTA, Goniopora(2), Acropora(2),Brain, Moon, assort zoas, yel& G star polyps, R&G open brain, P&B ricordia, montiporas, cup&candy corals, enias,B/G mush,flower ane(2), cherry red mussa, dusters,cleaning crew  |