Check if a pool's filter is properly sized for the pump flow rate and pool volume.
Check pump curve at your head pressure. Typical: 40-80 GPM
Square feet for cartridge/DE, or diameter in inches for sand
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An undersized filter is one of the most common equipment problems pool pros encounter. It causes high pressure, short cleaning cycles, poor water clarity, and premature filter media failure.
Unlike pumps (where oversizing wastes energy), a larger filter is always better. Benefits of oversizing by 50-100%:
For 8-hour turnover: you need ~42 GPM. For cartridge, that's 125-170 sq ft minimum (recommend 200+ sq ft). For DE, that's 42-60 sq ft. For sand, a 24" tank is minimum (30" recommended).
Practically, no. A larger filter just runs at lower pressure and needs less frequent cleaning. The only downsides are physical space and cost. Always err on the larger size.
Yes, in a good way. VS pumps typically run at lower speeds (1500-2200 RPM, ~30-45 GPM), which means even a modestly-sized filter works fine. The filter only gets stressed if you run the pump at high speed for long periods.
Possibly. First rule out: dirty/old media, clogged laterals (sand), or restricted return lines. If pressure starts high even after cleaning, the filter is likely undersized for the pump's flow rate. Reduce pump speed or upgrade the filter.
Water bypasses the media without being filtered. Cartridge pleats get compressed and bypass occurs. DE grids flex and pass debris. Sand gets channeled. You get high pressure and poor filtration simultaneously.
PoolDial logs filter model, size, install date, and cleaning history for every pool on your route.
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