I have an Aquatech cartridge filter. When I moved in about 2 and 1/2 years ago, I was told the filter was pretty new.
I've noticed sand coming out of the return jets, and it collects at the bottom of the pool. I've vacuumed it multiple times, just for it to come back through the jets an hour later.
I opened the filter and did a quick inspection of the cartridge a couple of times within the past couple of weeks. The cartridge media seems to have no punctures. The thing that confuses me is that whenever I take the lid off of the filter, there is sometimes sand and water on top of the cartridge. It looks like that water and debris is going above the cartridge. The cartridge looks white and nearly brand new.
Has anyone ever experienced this problem, or knows how to fix it? Is it likely that the pleats are clogged? The pool has gone green numerous times within the past couple years, although it is usually cleaned every week or two weeks (I know it is excessive).