Equipment selection advice sought...

[bmoreswim]

I am working on the equipment section of our specs to take to PB’s for quotes. I have a few questions regarding equipment selection. Side note - One of the PB’s only works with Hayward equipment, or so they say. If true, I have no real concern about using it versus Pentair or Jandy. I’m looking for sizing thoughts/comments for pump, filter and SWG for the following setup:

18’ x 38’ IG gunite rectangle, 3 ½’ to 8 1/2’, approx. 27,000 gallons
2” suction lines separately to 2 skimmers (80’ total)
2” suction to dual main drain (30’ total)
2” return looped return line to 4 returns (130’ total)
2” pressure side cleaner line (leaning towards a Polaris 360 – no booster needed) (30’ total)
2” line to S.R. Smith TurboTwister slide (up to 35 gpm) reduced to 1 ½” at slide (35’)
Automatic cover
Oversized cartridge filter
Maryland (approx. 4 month season – no heater – will likely plumb for a heat pump though)
Electric cost $0.08/kwh
Full sun on the pool, very clean regarding tree debris, etc., and autocover on most of the time

I have tons of other details in mind but these are most that I can think that would affect the equipment specifications. Let me know if others would be helpful.

My very modestly educated guess is that a 1 ½ HP 2-speed pump would be appropriate. My thought being that I could turn the pool over in 12 hrs. at about 38 gpm which would be done at low speed. Then when the slide is on and/or the non-boosted Polaris is running, it would be at high speed. I suppose if the slide is running a lot, the 12 hr. filtration cycle could be decreased due to added return flow. Would a 500+SF cartridge filter for this setup allow me to only clean it once per season? The SWG’s come in various sizes. Would I get the largest size, the 30 to 40K gallon one? Does it make any sense to go smaller due the cover being on often? Not looking to be cheap, just to right-size things.

If you have specific Brand/Model recommendations on anything I’d be glad to have them along with any more general sizing thoughts. If anyone has thoughts regarding pumping/filtration regarding having the cover on much of the time would be interesting too.

Any and all comments are welcome. My goal is to provide a fairly detailed specification list/design to the PB’s stopping short of trying to be a know it all. I’m perfectly happy to listen to a PB’s thoughts on equipment/techniques and am/will be comfortable enough with my knowledge from TFP to not be led astray.

Thanks,
B’more

 

[mas985]

My very modestly educated guess is that a 1 ½ HP 2-speed pump would be appropriate. My thought being that I could turn the pool over in 12 hrs. at about 38 gpm which would be done at low speed.

I think you could get away with a far smaller pump. A 2 speed is a good idea but a 3/4 HP full rated or 1 HP up rated would probably be more than enough. Both the Maxflo XL and the SuperPump come in a 1 HP up rated 2 speed. The TriStar is a good pump too but you can't get smaller than a 1 HP full rated two speed which would be plenty and easily give you the 12 hour turnover on low speed.

Would a 500+SF cartridge filter for this setup allow me to only clean it once per season?

Definitely and a smaller one might too. I have a 20k pool with a 425 sq-ft cartridge filter and get no PSI rise in a full year so I could probably get away with a 325 sq-ft filter. With a cover, I suspect you won't need a very big filter but given the size of the pool and the flow rates I wouldn't go smaller than 325 sq-ft.

 

[Qwaxalot]

I absolutely agree with Mark's comments (although I wouldn't go less than 420 Sq. Ft.).
You'll need a 40,000 gallon rated SWCG.
You really don't need 2" lines to the slide or the pool cleaner.
Reconsider the pool cleaner too, I find a Polaris 280 (needs a booster pump) will outperform a Polaris 360 or 380, and be more reliable in the long run.

 

[bmoreswim]

Thanks for the thoughts and details. On the pump, it looks like I was overestimating my HP needs significantly. One question that I had when looking at the pump curves was why do they only tend to show the curve only for the low setting for a two speed pump? Wouldn't people also be interested in the high speed curve? The slide adds head primarily because of the height of 8' and the low settings are usually very low head. Though I'll be honest, I haven't calculated my head with the proposed pipes (or the slightly smaller pipes for the cleaner or slide for that matter). Just seems to be a missing piece of information in their documentation.

I will definitely think more about the cleaner. I don't have a real bias towards using a booster or not, but just thought that if the cleaning is pretty good without, then why add another piece of equipment. But maybe the cleaning is not as good as I would hope for.

Is running a pump for filtration with an autocover on as effective as without the cover on? I'm guessing that skimming is affected but hopefully less debris to skim too.

 

[mas985]

They usually do show the high speed setting. Depending on the pump line, it is labeled as the single speed. So if you are looking at a 1 HP up rated two speed, the high speed head curve is the same as the 1 HP up rated single speed. This just avoids showing the same thing twice.

 

[UnderWaterVanya]

RE: 380/280 vs. 360 Polaris

The 360 is supposed to do a fair job but take longer per cycle than the 180/280/380 booster assisted cleaners. The 360 also may require that you take the time to close off 1 or more of your returns to get enough pressure to operate it.

 

[mas985]

I would go with ThePoolCleaner either pressure side or suction side. It doesn't require a booster and it requires less pressure and flow rate than any other non-booster cleaner.

 

[bmoreswim]

Thank you for the advice and comments. All good food for thought.