Hi Matt,
I assume the Hayward Power-Flo LX pump is a single speed, it always "sounds the same" (model SP1580X15TLFP). Horsepower is 1.5 and there is only one return and yes, the valve is on filter. OCLT results:
Last evening @ 7:05pm
FC 11.4 (57 drops x.2)
This morning @ 5am
FC 10.8 (54 x.2)...