More or less a newbie, as I bought a house with a pool last year and had to get it useable. I went online to figure out all the pool chemistry and such, and got it adjusted after 1 month+ of experimentation. The homeowners pool inspection didn't find any major issues, though it said the skimmer would need some repair/replacement, but it worked fine as far as I could tell.
I'm finally getting around almost a year later to understanding/doing serious maintenance (had to replace parts to the Polaris 380 APC when things broke). The weir broke on the skimmer, and am replacing that, but I noticed that there was a spaceship thing with the stuff left behind, and finally figured out it's the float valve to the U3 skimmer (now Pentair). Luckily I didn't throw it away. It was not installed when the house was bought. The skimmer seemed to work fine without it, and I was careful to maintain adequate water level for skimmer operation, but I'm trying to understand and maybe put it in, since my online readings indicate it's needed if the water level drops too much. With the drought in our area, I may not be paying as much attention to it as I should, and don't want to lose pump priming. There are 2 holes in the skimmer, and the one I assume is coming from the main drain is not plugged, and does go down, the does a 90 degree turn, so I'm assuming it's in use. There is a drain in the bottom of the pool.
My question is, do I just put it in underneath the filter? Is there something special that needs to be done? My understanding is that there's an o-ring, and it needs a good seal for it to work properly. I also don't know how to adjust the flow (there's something called a trimmer plate?), or HOW much flow is needed. Any help, or pointers to FAQs about this, would be appreciated.
Also, any info/pointers to FAQs on skimmer maintenance would be appreciated as well. I've gotten lots of info on pump filter cleaning (thank you youtube).