Skimmer not skimming much

[Palmharbor12]

Hello,

I moved into my house about 1 year ago. The water surface was always clean. The pool is enclosed in a cage. However, about 2 months ago I started to notice bugs on the surface, like the skimmer wasn't working. The water level is halfway up the skimmer door and there is some swirling inside the skimmer, but I can sit next to the skimmer and watch the bugs/dirt float past the skimmer. It seems they need to be within 6 inches for the skimmer to pull them in. Everything else floats by. My water pressure seems to be fine as the waterfall is flowing as usual and both return jets are blowing water out strong. I replaced my filter since it was 1 year old hoping that would help, but nothing changed. I have 2 floor returns. When I shut those off, so water is strictly going through the skimmer, the skimmer does a little better, maybe sucking in bugs/dirt from 8-10 inches out but lots of stuff still floats by. Any ideas? I do have a torn screen in one roof panel so I probably am getting a few extra bugs but I still think the surface should be clean. I also see pockets of bugs floating around the edges that dont seem to move but the return jets make big ripples on the surface so the water is definitely moving, just not at the surface it appears. I'm totally stumped.. any ideas?? Thank you.

[Denniswiseman]

The floor returns and main drain do very little so leave them off for normal operation
Try adjusting your other returns to move the water on the surface more tothe skimmer