Buying a pump for a huge 55000gal pool - input needed and appreciated

[makesumwake]

Just bought a new house with a huge 55000 gallon pool (size is listed on the original architect drawings).
i need to buy a new pool pump and im trying to select the best fit for my situation.

Plumbing size = 2in
jet outlets into pool = 3
filter: sand filter, Pentair TA-100D, 100gal/min max flow rating

flow rate for water turn over in 12hrs = 76 gal/min
flow rate for water turn over in 8hrs = 114 gal/min

Im fine with running the pump longer in order to turn over the water slower and use less power, and not exceed my sand filter capacity.
the architect design called for a 1.5hp pump, but i might be able to use a 1hp and save some money?
i just need enough suction to work some sweeping equipment, maybe some automatic pool cleaning equipment, and get the water flowing to turn over in at least 13hrs.

Im also considering going with a salt water chlorine generator and a automatic cleaning device to eliminate most of the maintenance.

thanks for any input

-Phil

 

[jblizzle]

Welcome to TFP!!!

That is a lot of water and while we usually say that turn over does not matter, running at low flow rates for short periods of time may not keep your pool very clean (the chemistry will keep it algae free, but you have to get the dirt out).

We usually say get the smallest 2-speed pump that will provide you with enough flow rate for any equipment you have. This can save you power costs by running on low almost all the time. If you are trying to run a suction cleaner all the time though, then you may not be able to run on low speed. Honestly, with a pool that big, a suction cleaner is not the best choice. You would have better luck I think with an electric robot. And then you could run a smaller 2-speed pump on low speed for circulation and filtration.

 

[makesumwake]

Jason, thanks.

Could you explain the need for a 2 speed pump? low speed will be the speed needed to circulate the water in 12hrs min for a complete change over, or about 1hp to 1.5hp. however, 1hp or 1.5hp is already enough power for suction to clean, etc. if i put more power than 1.5hp to the sand filter, i will exceed the sand filter limits and get sand into the pool, since max flow for the sand filter is 100gpm, and i will already have that flow with a 1.5hp pump.

 

[jblizzle]

I would not go larger than the pump have, but would get a 2 speed. On low you will move half the water for a quarter of the power cost. Turn over is generally meaningless. See the pump run time article in the How To section of Pool School.

 

[makesumwake]

ok, thanks i read the articles. so you would recommend a small 2-speed pump? which 2 speed pump would you recommend?

thanks

 

[sargent]

Here are my thoughts. I could be wrong, so maybe Jason or somebody else will jump in. First, if you are going to have a SWG, then it would probably make sense for you to have two operating in parallel for your size pool. The minimum flow rate is around 20 gpm for the SWG, so you would want double that flow for two in parallel. Assuming you will be running on low speed with a two speed pump, that would mean something like a Whisperflo 1.5 hp, which would give you 41 gpm. Or a Superflo 2 hp, which would also give you 41 gpm. (This is based on the Pool Pump Tools spreadsheet using plumbing curve C.)

Or - and this is what I think I would do - you could get something like a MaxFlo VS pump for about $150 more than the two-speed Superflo. Then you could adjust the flow to just what you need, probably around 1800 rpm to give you 42 gpm. If that is too much or too little flow, you could adjust as necessary. It would take a few years to pay back the difference in cost, but the beauty of it is you could adjust the flow to just what you need.

If you had a smaller pool that only needed one SWG, or if you weren't considering a SWG, I would recommend a 1 hp (or perhaps a 1.5 hp) two speed pump, SuperFlo, SuperPump, MaxFlo, or FloPro.