I have an in-ground pool and have been learning this for the past 10 years. Over the past 2 or 4 weeks, the return flow is very low.

I have a Hayward pump, a Hayward cartridge filter, and no heater.

When I fist noticed, I didn't think it was my filter because I had cleaned it 2 weeks prior. But I took a chance and cleaned it again, and sure enough, the flow picked up again.

At a normal flow, the gage on the filter as 15 psi. When I started having this problem, the psi was at 25. I cleaned the filter and it back to 15 psi. But ever since, it's been at 25 psi, and even if I clean the filter, it never goes down to 15 psi.

I also changed the seal over the skimmer backet of the pump. I see no leakage of water arounf the pool equipment. The skimmer backet of the pool is empty. The pump seem to be running just fine.

This morning I threw in my sweeper that's connecting to the skimmer basket of the pool, but it doesn't seem to be sucking.

The filter is barely 1 year old.

Anything else I should be looking at?