u/Foo3133

Can anyone please help me identify what the smaller pvc pipe is right at my water line? The bigger one underwater is the autofill. For context, no water comes out, so it’s not a return line. I’m not 100% positive if water goes in or not, it’s hard to tell. But I bought this house almost 1yr ago and it looks like the old waterline is above that pipe, but I’m afraid if it’s an overflow drain, then my auto fill will just be constantly running to offset if that’s an overfill drain. For more context, the water level at my skimmer is a little below halfway up, so when I turn the blower on, it almost sucks air, but eventually evens out. Any help would be great, thank you!!