What size Pump?

[richmgreen]

I've read the lessons on head loss, velocity, etc etc. However, when I look at the chart of Total Head to Flow. If my numbers fall between pump sizes, should you go with the lower 1 HP fro me or upsize to 1.5 HP?

I have 26,730 gal pool (18x36x5.5 x 7.5) @ 8hrs turn that is 55.7 (56gpm) flow. I'd like to get about 60gpm flow to turn over a little more. Total Head estimated to be around 46 (17 on pressure gauge x2.31 + 5). Using the attached Hayward Head to Flow chart, it shows between 1hp and 1.5 HP. I will also be eliminating my depend main drain this spring. That will prob change my numbers. The distance of the piping from my skimmer is about 26 feet. I am upsizing my sand filter from the S220T to the S244T for a higher flow rate.

Should I go with 1hp or 1.5hp ? and while the ditch is open, should I change all piping to 2" vs 1.5" .... or maybe just the suction line to 2"?

Please help !!

Thanks,
Rich

 

[duraleigh]

Mas985 can get into the math and hydraulics. From being on this forum a long time and reading what he posts, I can say that a full rated (not up-rated) 1HP pump is perfectly adequate. The S244T filter is big enough for that pump but a little too small for the 1.5 full-rated pump.