Algae in skimmer mouth of closed pool

[V___25]

I peeked. I took off a corner of the cover because I hate not knowing what's going on under there. The water looks great, I can see straight down to the main drain including a huge pile of worms and leaves .
However, I noticed some bright green algae on the bottom of the skimmer mouth, like growing on the plastic. Should I try to get in there now and scrub that off now or is ok to wait until we actually open in late April/early May? How would even be the best to tackle that? A magic eraser? Just use a sponge and wipe it off? Should I try to pour some bleach in there? There's water in the skimmer so I can't pour anything directly on the algae. Should I attempt to test the FC? I'm assuming if there's algae on the skimmer mouth the FC is below 3.

 

[Newdude]

Should I try to pour some bleach in there

You don't want whatever doesnt mix seeping out of the skimmer and down the vinyl wall.

Should I attempt to test the FC?

That's what I'd do. If you have any FC, then use a sponge or scrub brush and let the water have at it.

If you can pop that corner you can add FC if needed, but you'll need to brush that area good with no circulation.