Pipe Size For New Pool

[borne]

I am having a pool put in and about 1 week from digging the hole. The pool is small - approx 12000 gallons + 500 for the spa. Because of a recent new law that affects pool pumps, the builder does not yet know if my pump will be a 1 hp or 1.5 hp. If it is a 1 hp, he is saying 1.5" Dia. pipe will be sufficient. If 1.5 HP, he says he will install 2" pipe. Does this seem OK? Should I have them install 2" pipe even if the pump is a 1 HP?

Also, for the suction lines, since I'll have 1 from the spa drain, 1 from the pool drain and 1 from the skimmer, do those really need to be 2", or can they be 1.5" until they T together?

Thanks in advance.

[Pool Clown]

If he puts 1.5 pipe in the ground, you won't be able to up size the pump (if you needed/wanted) down the road. Have him put 2" regardless of what size pump goes in. Leave your options open.

[Pool-newb]

That gets my vote also - definitely go with 2" plumbing. The cost difference is minimal but it can add up to a lot of savings over the lifetime of the pool.

I recently installed an over-dimensioned two speed pump and I really wish the builder had used the 2" pipe because I now get cavitation (bubbles appear in the water without a leak present).

I am able to use the high speed to have a fast turnover - good for mixing or quick filtering on dirty conditions. For daily filtering I leave it on low speed and that reduces energy usage and pump noise.

I also recommend putting ball valves, disconnects and labels on every pipe coming out of the ground. Helps a lot with troubleshooting, holding prime when cleaning pump basket, and other cleaning tasks.

I would also recommend the variable or multiple speed pump. High speed on mine is 1.5 hp, low speed is perhaps .75 hp but it uses less than half the electricity because flow resistance drops exponentially as flow speed drops.

I found mine online for perhaps 10% more than my local pool store would have charged for a replacement single speed pump.

[billp]

You really need a different pool builder. This one knows nothing about hydraulics or pump sizing. New law or not... he is living in the 60's...

[Pool Clown]

You really need a different pool builder.

I don't think that is an option this late in the game. Are you checking the date of posting on all these treads you're answering? Alot of them are over a month old.

This one knows nothing about hydraulics or pump sizing.

How can you make this assumption? You don't even know how long the plumbing run is.

he is living in the 60's...

Theres no reason be disrespectful. Especially when he (the builder) can't respond.

Pools were built in the sixties, with open-faced impellers, 1 1/4" to 1½” lines, and sparkling clear water. Why is it we need to go excessively big?

I thought the new trend is run less hp and run longer? Do we really need go big with plumbing if were shooting for lower flow rate? Besides, anything bigger than 2 1/2" pipe, with 1 hp (I know he said 1 or 1 1/2 hp) is not only over kill, but cost prohibitive.

We try to help others here by guiding them with problems/ decisions with their equipment or a particular situation. I don't think they appreciate being told they made a wrong decision with your first sentence, or they should have gotten this pump, or that filter is no good you should have gotten...

Perhaps on occasion they could exchange a piece of equipment, But its hard to get a refund on labor or material in the ground. Lets try to help them with what they have. So maybe just answer the question posted, in a timely fashion.