Pool Repair 1.5" vs 2" pipe

[richmgreen]

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.

Thanks
Rich

 

[jblizzle]

I would stop thinking about flow rates. Definitely a good idea to upsize the sand filter as you can go longer between cleanings but has nothing to do with flow rates really. Given that it sounds like you only have one suction line coming from the skimmer at a minimum that should be increased to two inches. The return lines could be left at one and a half inches although there is no harm in making them two inches as well.

Finally you are correct that getting a larger pump is not likely required and would cost you more in the long run.

 

[richmgreen]

It's ok to have a 2" suction line and 1.5" return lines. ?

 

[ewkearns]

Yes! Actually, it is preferred practice in most situations.

 

[richmgreen]

Thanks! They are also going to put both returns on the same side as the skimmer. One deep end and one low end. Right now one is on skimmer side deep end and the other is on opposite side low end. I also have two in the stairs that will stay there. Any issues with that?

I'm told you can aim the eyeballs down at 45 deg angle to get proper flow ?

I'm a little concerned.

 

[ewkearns]

IMHO, returns should promote circulation. It sounds like their plan isn't going to do that. When they re-did my pool they ended up with one return basically "pushing" against another. After a few quality hours watching a tennis ball floating around, I concluded that it just wouldn't work the way I wanted. This fixed it and gave me back the "lazy river" effect I wanted.

https://www.mypoolyard.com/product_...1410f-p-4537?gclid=CM6j_sHE88oCFYwfhgodQR4AxA