Learn something every day
What purpose does the membrain serve in an RO system. The reason I ask... This a Costco Watts Premium System WP-5 There is no DI on this system. The water volume has always been such that I fill up the 3 gallon pressure tank and when that runs out it took a couple of hours to fill it up again. Recently the hose just flows almost freely for as long as I want. I just replaced the filters and it still flows freely. It says the membrain is good for 2-5 years and it has been 1.5 Do I need to replace it?