Cement around skimmer raising/lowering

[Charliepool]

Hi all, I’m looking for some advice. I’ve got an old Sylvan pool. The cement block around one of the skimmers is raising on one side and lowering on the other. I’ve been in the house about five years and I would say it’s moved about a cm in that time. I’ve attached some pictures, you can see where I put some concrete and caulking to fill the gap on top between the pool coping and the cement block where the skimmer is.

You can also see inside the skimmer where there is a big crack/hole on the right side.

Questions:

1) should I do anything about this? Try to dig out the back side underneath and backfill with concrete?

2) should I fill the plastic hole inside the skimmer? With caulk? With epoxy?

I would really appreciate some advice. I just got the pool plastered so am not going to do anything major.

 

[Charliepool]

Here is a better pic of the crack.

 

[Bperry]

Here is a better pic of the crack.

They make epoxy putty for the cracked skimmer housing but it’s usually temporary or needs to be reapplied frequently, especially where you have big freeze that cycles. Only other option is digging it out and replacing it.

The sinking deck can be corrected, need to lift the back edge up and backfill. (Hydraulic jack or pry at) Can backfill with construction grout that flows more easily that pure concrete. Could also pack it with gravel or stone.