New pool owner, I'm noticing some bubbles on one of my returns and saw another post recommending to check the pump o-ring. Is there supposed to be an o-ring on top of the strainer basket? I have one recessed in the pump lid, but looking at the pump manual it looks like I should have another one that just rests on top of the pump basket. Before I go out and buy another o-ring I figured I would ask here first to confirm.