percula99
New member
I have a 90 GPD RO unit with an add on pressure gauge that I bought seperately. I replace the sediment and carbon blocks when the pressure goes from 60 PSI to 30 or so, which happens about every four to five months. The water pressure going from the house to the unit is 65-70 PSI. I repace about 5 GPD due to evaporation, and do a 50 gallon water change once a month on a 180 system. That means I make about 200 gallons per month. After 5 months I have made 1000 gallons and I really must replace the pre-filters. Does this sound about right to most people or am I not getting long enough life out of them?