150lb Hayward Sand filter w/a 1.5HP motor overkill

GCS

Well-known member
Jul 28, 2008
161
I have an 18' x 48" Intex Metal Frame (roughly 6,000 gallons)

I have found a 2 year old Hayward 150lb Sand Filter (has brand new sand in it as well) with a 1.5HP pump locally for $100.

Is this going to be overkill for my pool, will I have problems with it having too much power for the pool?

Greg
 

Crzyfrlss1

LifeTime Supporter
Jun 6, 2008
161
Central, CT
It may or may not be overkill but for that price I'd get it.

You could always sell the motor on Ebay and just put a 3/4 or 1 hp motor on that filter.
Look in my sig for what I use as a motor, I got it for $99 shipped on Ebay and it came with a strainer basket too.
 

TomU

LifeTime Supporter
Apr 22, 2007
93
Wyoming, Michigan
In my opinion, the pump to filter size is more of an issue than the pump to pool size. Filters are rated for a max flow rate based of the surface area of the sand. With an AG pool, there is not normally the same amount of head loss in the plumbing that one would see with and IG pool. Because of this, its very possible that with that motor/filter combination you could very well be above the designed flow rate for the filter. You could remedy this restricting the return back to the pool some (either a smaller return, or a ball valve partially closed), but you still will be paying the electricity to run a 1-1/2 HP pump (OK, a little less with the reduced flow, but still probably more than a 1 HP would cost to run).

Do you know what size the filter is (diameter)? The typical designed flow rate is 20gpm/ft2. Here is what that works out to for different filter diameters:
  • 18" - 35gpm[/*:m:i222hjrr]
  • 20" - 43gpm[/*:m:i222hjrr]
  • 22" - 53gpm[/*:m:i222hjrr]
  • 24" - 62gpm[/*:m:i222hjrr]

The other factor that could be mentioned is turnover rate. Normally people shoot for 1-2 turnovers per day. With a higher flowing filter/pump combination, you could potentially be turning over the water very quickly. It probably isn't a good idea to complete a turnover in 2 hours and then leave the pump off the rest of the day (stagnant water is usually bad), but running for longer means your getting more turnovers with potentially diminishing returns.
 

Cherie

LifeTime Supporter
Jul 23, 2008
507
Wylie, Texas
If I may chime in here with a question as well. I am about to purchase a 2-speed Pentair Dynamo to lower our electric bill. We have an 18" SD40 sand filter (with zeolite) and 1.5" piping (actually, it's still the tubing right now - until we hard-plumb it). We're currently running a 1hp Pentair Dynamo and really like the Dynamo.

Our situation is that, in addition to wanting a 2-speed pump, we will be adding a 2nd return in the shallow end to help with circulation. So would the Pentair 2-speed work for us? From what I've researched already, it looks like it would. BBBUUUUTTTT, my niece tells me that her store sells a 1.5 hp, 115 v., Pentair Dynamo 3-speed! I can't find one online and she hasn't called me back yet today.

If she was mistaken about the 3-speed, this post will be moot. However, if there is such a Dynamo, will that work for our pool as well, or should we just stick with having her order us a Pentair Dynamo 2-speed? Her 1.5 hp could well be an uprated model - don't know, since I can't find it online (while waiting on her to call me back). If she DOES sell a 3-speed, I'm thinking that the middle speed would be better for us, if we're going to add a 2nd return line, which, in my understanding, will add to the resistance flow.

Any info would be appreciated! Thanks.
 

Hotrod30

Platinum Supporter
LifeTime Supporter
Dec 22, 2007
504
Central New York

Cherie

LifeTime Supporter
Jul 23, 2008
507
Wylie, Texas
Thanks for the links HodRod. I'll look them over tonight, so I can be more informed when (IF) my niece gets around to calling me back!
 

TomU

LifeTime Supporter
Apr 22, 2007
93
Wyoming, Michigan
Cherie said:
...we're going to add a 2nd return line, which, in my understanding, will add to the resistance flow.
No. Adding another return will LOWER the resistance to flow. It's the same as increasing the pipe and return nozzle size. The volume and speed of the water coming out of the return will be reduced since now its split between two returns. I would expect to see the pressure gauge on your filter drop some when both returns are open. By making it easier for water to return to the pool, I would also expect your flow through the filter to increase slightly as well.
 

Cherie

LifeTime Supporter
Jul 23, 2008
507
Wylie, Texas
Thanks for the info, Tom. I did, indeed, have that backwards, didn't I? And here, after all that reading, I thought I had it down!! My brain is almost jello from all the studying on how to take care of our pool - and trying to get better circulation.

We're waiting on The Circulator, which will hopefully arrive one day this week. So our hope is that, with The Circulator going and running a 2-speed on low 24/7, we will have a lower electric bill with better circulation. We'd really rather not have to add a 2nd return.

Thanks again for your help!