I have a Pentair/Sta-Rite System 3 cartridge filter. The filter is 1 year old. Last year it ran without issue. This summer, I took on the pool maintenance (away from the PB). I wanted to lower the pump speed to reduce energy use, as it was previously set to run at 2500 rpm. I also have a Pentair salt chlorine generator (CG), and the CG requires a minimum flow rate to keep it running. I recently cleaned the cartridge filter and was able to run the CG at around 1600 rpm, significantly cutting the energy usage at the circulator pump. However, after only a few days, I was getting an error from the CG, indicating flow rate was too low. I bumped it up to 1800 rpm. Okay again for a few days. I opened up the main filter again, and noticed that the air bleed screen/filter was clogged with a sand/sediment mix. I cleaned the air bleed screen, reassembled the filter, and the system (CG) is again okay to run with the pump at 1600 rpm (or even lower). For whatever reason now, the filter air bleed screen is now getting clogged less than 24 hours after cleaning. If I clean just the air bleed screen, the system will work again, but only for a short period of time. It's almost as if the air tube is pulling water through it, trapping debris in this small screen. Clearly (at least to me) this is not how the main pool filter should be working. I'm stumped as to what to do. Any suggestions would be appreciated.