|
When the rejection rate or efficiency drops. Depending on what membrane you have, it was somewhere between 90% and 98% efficient when new. Most 75 GPD and less membranes are 96 to 98% rejection rate(efficient) while some 100GPD membranes are as low as 90% rejection when new.
To test the rejection rate or efficiency you need a TDS meter to test the Total Dissolved Solids content of the tap water and then the RO water. The RO water should contain 98% less TDS than the tap water does or very close to it. Depending on how bad your tap water is to begin with a 1 or 2% difference can make a big difference in the life of a DI filter if you have an RO/DI system.
Membranes typically last 2 to 3 years if taken care of. By taken care of I mean changing prefilters and carbons every 6 months as recommended, disinfecting the housings at least annually and using high quality replacement filters not hardware store or e bay varieties.
|
05/18/2007, 03:55 PM
Linear Mode
