So, I inherited a pool. It's been a steep learning curve. My current task is figuring out a best practice for vacuuming, which brings me to the question of why I have two "holes" in my skimmer, and no, I don't mean inflow and outflow in one skimmer basket, I mean I have what you might call a dual or twin skimmer, I think... See attached pic. I tried covering one of them then using a vacuum plate but my pump ended up surging, which hasn't happened before, so I hastily shut the show down. Wondering now if there's a correct method for setting up to vacuum with a system like this as pretty much everything I'm finding online related to just the one skimmer with basket...