Dropping in to the pumphouse, my original intro thread and so forth is here if for some reason you need a reference: green-water-moved-topic-from-introductions-t58765.html
In any event, you can see my filter / pump setup in my sig, and I didn't realize it previously, but after watching some youtube videos and reading a whole bunch of stuff in this section of TFP, I realize that I seem to have a relatively large suction-side leak.
Here's the symptom: pump basket is "churning" - so there's a pretty decent amount of air mixing up with the water. I tried to use the shaving cream method to detect any leaks pre-basket, and post skimmer - with no luck. I've not yet tried the water on the joints method, as I'm using the hose to try and fill up the pool some more (it seems to me that the water level might be a touch low, so I'm going with the "simple" things first.)
However, while the pool is filling up some more (on 4 screws of the skimmer, my water line is probably between the 2nd and 3rd ones up), I noticed that my sand filter was "gurgling". Wanting to see what's up with that, I decided to take the multiport valve off, and very very briefly (maybe 1 second) ran the pump with the collar off, which obviously shot water onto my pants Anyway, when I put the collar back on and tightened it down, I noticed that the "churning" in the pump was much less than it has been previously. It's still churning mind you, but it's much less worse.
So, I'm asking all you wizards, is it possible for the filter (pressure side) to become vapor locked or something like that, and "cause" a greater pull than would normally occur, thus blowing air past the basket o-ring or other joints that are normally air-tight? I know nothing about hydraulics, and I've tried to read about head and suction and all that jazz in here, but honestly it might as well be greek.
Anywho, any advice on getting this churn / air gone from my pump basket would be super. I'm pretty sure that my vacuum (that I've been having a **** of a time with) would actually work if I could get this sorted / find out where the problem is.