I am having some pool repairs done that require them digging up the lines. Right now my pool (18'x36' rectangle with 8ft deep end) has all 1.5" piping. After reading about Hydraulics, I am considering replacing it with 2" piping. Is there any problem with having a flow rate that is below the max velocity at 6ft/sec rate with 2" piping. ie., any issue by having "oversized" piping. Although, my gpm flow rate for turnover in 8hrs is about 56gpm. I have a 1hp pump. The pool people say go to 1.5 HP. Doesn't make sense after reading all the information. I will upsize my sand filter from S220T (52gpm) to S244T (62gpm). I am elimninating my main drain as well. Given all this, is it recommended I go 2" piping? and any issue with 60gpm flow rate through larger 2" pipe?
They were going to replace with 1.5". Now would be the time to upsize if it makes sense.