I would appreciate any ideas on the problem I’m having. Years ago, I replaced the original Pentair cartridges in my Pentair CCP 520 with Pleatco Advanced cartridges — no issues. Recently, after many years with the Pleatco cartridges, I decided it was time for new ones. On Google and Amazon, I saw several options, but could not find the same Pleatco Advanced. On Amazon, I chose replacement cartridges sold by In The Swim because they are an established name (They are owned by Leslie’s.) The new In The Swim cartridges worked ok for the first month, then pollen season hit. I cleaned them after one month, then again this past weekend after a lot of brushing and running the Polaris. My pool is very cloudy yellow/green. I use liquid chlorine every night and am keeping the chlorine level at about 5, so it would seem this is pollen rather than algae. I just ran the filter pump for 24 hours, but no improvement, the pool is still just as cloudy yellow/green. The filter pressure gauge is not rising much — over the past week it has gone from 17 to 18 psi. These In The Swim cartridges seem to fit perfectly, but the material is different than the Pleatco cartridges. When I clean the In The Swim cartridges with my hose sprayer, they clean much more easily than the Pleatco — unlike the Pleatco, the pollen, or algae, doesn’t seem to stick to the material. Maybe these In The Swim cartridges are more porous, or perhaps they not seated perfectly in the filter and the water is getting through without getting filtered by the filter material. Any comments would be appreciated.