Originally Posted by Larso
I would have thought a buildup in the 5u or 1u would just result in a reduced throughput?
As prefilters clog and rob pressure from the RO membrane, the membrane performance (how well it cleans the water, a.k.a. rejection rate) drops. In residential systems, the drop is severe at the lower end of the pressure range (e.g., less than 40 psi).