Pool builder says 3" pipe is waste of money

[57cheby]

I told builder I want 3" suction and return lines on spa and I also had them run 3" suction on pool drains. I have Pentair intelliflo 3hp vsp. He tells me I'm wasting my money. I have read on here of people complaining about low pressure on spa because of pipes too small. Builder says all I need is the 2.5" to spa. I know it's on here somewhere but can't find it tonight. To all the pros would you run 3" pipe to and from spa?
installing 8 jets 15 gpm each.

 

[mas985]

How many jets will you have?

How much flow rate per jet?

 

[57cheby]

8x 15 gpm I just edited post. Thanks

 

[mas985]

Sorry one more. How long are the runs?

 

[57cheby]

I can measure in the morning but guessing 40ft each way.

 

[mas985]

The first issue i see is that you need 120 gpm for all jets. The Intelliflo won't be able to do that even with 3" pipe.

But even if it could then you have the issue of pushing 120 gpm through a filter. With that many jets, you really need a stand alone pump for only the jets. The spa should have a separate filtration loop from the jet loop.

 

[Titan7]

I have 3" section on pool and spa, 2" returns 6 jets, the spa run is 65 ft. 1 pump, plenty of spa jet action.

 

[57cheby]

Thank you both for your help. I had 9 jets put in and after reading on here where some people didn't have enough pressure I ran out side and had him cut one out, should have stuck with 6. PB is also using a 2hp blower and said usually has to turn pump speed down cause jets are too strong. I will go ahead and do 3" suction and 3" return and hope for the best is all I can do at this point. Thanks again

 

[Isaac-1]

There is really no down side to oversizing the plumbing except for the minor increase in up front cost. Within certain sane boundaries large plumbing is always better with lower flow restriction, which in theory you will get back eventually on electrical savings / increased efficiency. The only factor here is that as pipe size increases you get a case of diminishing returns so that the payback time on "savings" may be years or decades.

 

[57cheby]

My thoughts exactly. The PB made me second guess myself. Thanks for your help

 

[KatyTXPoolOwner]

I insisted to my PB that he install 3" return and suction for my 8 TwirlyBird jet spa (about a 50-60' run) and I'm fortunate that I stood my ground. Just my Pentair VF pump and Blower would not supply nearly enough spa jet action. He ended up installing an additional Pentair VS pump in the spa only loop and the spa has fantastic spa jet action. I'm not sure if 2" or 2.5" suction/return would have the same result.


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