What filter is best under big trees?

[andybuildz]

My Pool 15x40 and around 17,875 gallons. Two returns and one skimmer. I'm under a lot of big old oak trees and some pine trees here on Long Island in NY, all of which I've cut back as best as possible. I'm in need of a new filter I think b/c I keep having to replace parts in it which i do myself. I do everything myself including all the coping and paver work you see in the top photo and re-resurfaced the busted areas of concrete, then repainted with a 2 part epoxy paint. I have a decent test kit and a good Dolphen robot ($1000) I use 4-5x a week.

I cant keep the water clear like it is in this photo...doesn't stay that way for long after I open the pool like in both photos. I have a Hayward S-200 sand filter with a Hayward 1HP pump. The filter is old and I've rebuilt it more times than I wanted to. Changed the sand numerous times.

What filter is best for under trees?

I'm thinking of switching to a cartridge filter., seems as though it would be easier than changing the sand every other year. I back wash as much as necessary too. Would a new cartridge filter help? What kind of filter would you use, and do you think that could be my problem?
TIA

[Denniswiseman]

Cartridge filters are better at filtering but you still have to clean them especially if you have a lot of debris
You don't have to keep changing sand
If the water is cloudy then you have a water balancing problem or need to Slam (Shock Level and Maintain)
Let's have your numbers
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pH:
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