Pipe Size for Small Inground Pool ?

[AndyDW]

Hello I am installing a small 12 by 22 by 55 inch deep inground pool (9000 gallons). I am planning 1 skimmer and 2 returns, bringing all lines up to equipment pad. the farthest return is 45 feet, the other is about 35 feet. the suction line run is 50 feet. the equipment pad is about 2 feet lower than water level of pool. purchased a hayward max flow vs variable speed pump (rated up to 1.5 hp). all this said, will I be OK with 1.5 inch pipe throughout, or is there a significant benefit to going with 2 inch pipe on skimmer line and all 2 inch fittings at pad (reducing to 1.5 inch only where necessary). im planning to purchase a zodiac mx6 suction cleaner and a swg.

I would appreciate thoughts from the experts on this forum.

 

[ajw22]

Welcome to TFP.

Use 2 inch suction lines. 2" piping on the equipment pad. And 1.5" return lines. That will be more then adequate.

Consider skipping the suction cleaner and getting a Maytronics robot cleaner.

What surface will your pool be?

Construction Best Practices - Further Reading

www.troublefreepool.com

Equipment Pad Best Practices - Further Reading

www.troublefreepool.com

How to select pool equipment - Further Reading

www.troublefreepool.com

 

[AndyDW]

the pool will be vinyl, icf construction. I read somewhere on the forum that you should maybe go bigger on the suction line vs the return pressure lines. I'm planning only a single suction line on skimmer, meaning when cleaning you'd lose the skimmer which concerns me a bit. was even thinking of a second suction line or a side port that I could turn on when cleaning (via a ball valve or jandy valve) and off when not in use for cleaning. obviously a robot avoids this issue. do you have a model of the maytronics you'd recommend?

 

[ajw22]

the pool will be vinyl, icf construction. I read somewhere on the forum that you should maybe go bigger on the suction line vs the return pressure lines.

That is why I said 2” suction and 1.5” returns above.

I'm planning only a single suction line on skimmer, meaning when cleaning you'd lose the skimmer which concerns me a bit. was even thinking of a second suction line or a side port that I could turn on when cleaning (via a ball valve or jandy valve) and off when not in use for cleaning.

I always recommend two skimmers. If you have one skimmer and it has a problem your pool is shutdown. If you have two skimmers then you can use your pool while you get it fixed. An additional skimmer and some pipe is inexpensive.

obviously a robot avoids this issue. do you have a model of the maytronics you'd recommend?

Call Margaret Mills at Marina Pool, Spa, and Patio in Lakewood CO and see what she has and recommends.

 

[JamesW]

That is why I said 1 1/2” suction and 2” returns above.

That's reversed.

You want 2" suctions and the returns can be 1.5".

 

[ajw22]

That's reversed.

You want 2" suctions and the returns can be 1.5".

I've been backwards all week. That is why my pants don't fit properly.

 

[AndyDW]

great. so a 2" suction line to the pad with the pump about 12 inches below the water level, and then 2 x 1.5 " returns back out to the pool which I could throttle individually if need be. I'll get 2 way jandy valves for all 3 lines. to be energy efficient, I'd like to run my vs pump on as low a setting as possible and at 1000rpm it says it will do a flow of about 25gmp at a tdh of 5 feet. I looked at some charts and found that 1.5 inch pipe has a friction loss of 4.6 feet on 100 feet of pipe, and I'm only running 80 feel. so I think I will be good. my only concern is whether I would have the flow I need at the skimmer at this setting. I think I will, any thoughts? also, would there be any benefit to raising the pump ? thank you very much for your help with this. my mind is exploding trying to understand all of this.

 

[ajw22]

You will be fine. The head losses you are worrying about will not make any visible operational difference.

 

[AndyDW]

again my pool is under 9000 gallons so 25gpm would be a turnover of 6 hours... which reading through stuff should be plenty.

 

[AndyDW]

excellent. thanks again for all of your help

 

[ajw22]

again my pool is under 9000 gallons so 25gpm would be a turnover of 6 hours... which reading through stuff should be plenty.

Turnover is a myth and does not matter.

Many pools run with a turnover of less then 1.

Determine Pump Run Time

To figure out how many hours you need to run your pump, you need to know how fast your pump works. You can find this here.

www.troublefreepool.com

 

[AndyDW]

great very informative article. thanks for pointing me to it !!

 

[Kenepo17]

Getting ready to move the chlorinator 3 feet away from heater, also adding a cv and heater bypass diverter valve. Question: should i replace all 1 1/2" piping to 2"? Everything circle red is 1 1/2" rest is 2". According to my PB all way from pool piping is 2" except coming up and going to ground is 1 1/2".