I'm into my second year with a pool and basically my first pool opening (last year a pool installer put a new liner in so I didn't have to deal with removing a pool cover - I never put one on the year before).
The pool is covered with a micro mesh winter cover (no pool pillow). As per provided instructions, I let the mesh cover be slack over the pool, so some water seeps above the cover. I'm looking at opening the pool this week and green algae / pollen is floating in the water you can see above the mesh and I'm strategizing how to get the cover off without dumping the green floating stuff into the pool. I haven't yet looked under the cover for the current state of things. That will happen soon of course.
I was thinking of a pool pump to siphon off the green stuff with a hose out to the yard. That might work but I might also lose some decent pool water as the pump will suck water through the mesh.
I'm looking for any input from others who've faced this problem and what worked (if anything) and what didn't work (secret tips on getting such a cover off, etc). I called the company I bought the cover from and basically the tech said (paraphrasing) - "Some of that stuff is just going to get into your pool. That's what happens with those above ground mesh covers. We have great chemicals to get your pool clean in no time."
I do think the cover being left slack was a good thing over the winter as we got blasted with plenty of snow / blizzards during Feb and March. The pool walls never looked stressed as the ice that formed on top and below the pool provided nice support. But I don't want to regret using a mesh winter cover if I dump that green stuff into my pool.