My 1 HP Hayward Superpump died and I need a replacement. I'm trying to determine if I can reduce the pump HP, maybe even as far as an uprated Pentair 1/2 HP. The relevant numbers:
18'x36' oblong (oval with straight sides), 3 ft shallow end and 8 ft deep end approx 21000 gallons
(2) 1-1/2" suctions - 1 from skimmer, 1 from main drain
(1) 1-1/2" return line back feeding 2 returns
3.14 sq ft sand filter with Hayward multi-port valve - runs 10 or 11 psi when clean
I'm estimating 35 GPM at about 33 ft head for a 10-hr run time. I figure I will go with a single speed pump due to the SWCG that I have had issues with in the past (will post another topic in the proper place).
I'm confident I can drop to at least a 3/4 HP, but I'm wondering if the 1/2 HP can work. If I had to pick I'd rather run a little longer on a smaller pump than shorten the run time on a bigger one. Any recommendations?