The pressure-gauge rule
Note the pressure right after a cleaning; that is your baseline. When it reads 8–10 psi higher, flow has dropped enough to hurt circulation and it is time to clean. Write the baseline on the tank with a marker.
Cartridge, DE and sand
Cartridge: hose the pleats every four to six weeks in summer, deep clean (soak) every three to four months, replace every two to three years. DE: backwash when pressure rises, full grid cleaning every three to four months, recharge with DE after each backwash. Sand: backwash when pressure rises, deep clean or sand change every five to seven years.
Why Houston is harder on filters
Pollen in spring, dust from new construction in the western suburbs, and algae residue after every hot spell. Pools that just recovered from green water clog a filter within days and need one extra cleaning.
Questions
Can I just hose the cartridge?
Hosing removes debris but not the oils and calcium that blind the fabric. A soak in filter cleaner every few months restores flow; that is what our $180 filter cleaning does.
Is filter cleaning included in weekly service?
Backwashing and pressure checks are. The full disassembly cleaning is billed only when performed, $150 for weekly customers.