What is a common indicator that the RO pre-filter needs to be changed?

The common indicator that the reverse osmosis (RO) pre-filter needs to be changed is when the delta pressure exceeds 10 psi. Delta pressure refers to the difference in pressure before and after the pre-filter. When the pre-filter becomes clogged or saturated with contaminants, it creates increased resistance to water flow, resulting in a higher delta pressure reading. Monitoring delta pressure is a reliable method to gauge the condition of the pre-filter, as an increased delta pressure signifies that the filter is no longer effectively removing contaminants and needs replacement to maintain optimal performance of the RO system.

Other indicators, such as the duration of use or water taste changes, can be subjective and may not provide an accurate measure of when a filter should be changed. Relying on delta pressure provides a more precise and quantifiable method for determining filter integrity, thus ensuring the water quality remains within safe and effective standards.