Check filter pressure

What you are looking for Your filter has a clean starting pressure — the reading on the gauge right after you last cleaned the cartridges. Everything here is measured against that number, so if you do not know it, take this week's reading right after a clean and write it on the tank with a marker. ## What to do 1. With the pump running at normal speed, read the pressure gauge. 2. Compare it to your clean starting pressure. 3. If it is roughly 10 psi higher, clean the cartridges. If it is not, you are done — walk away. Pentair also calls out a noticeable drop in flow as the same signal. If the returns are visibly weaker than usual, treat that as the trigger even if the gauge disagrees. ## Why not just clean on a schedule Cleaning a cartridge that does not need it wears the pleats out early and costs you a filter. The gauge is the honest answer.