Which pool pump should I get?

[keithw]

I have a 6000Gal fiberglass in-ground pool. I use a Polaris 280 in it. Right now I have a low end 1 3/4HP pump combined with a Hayward 18" sand filter. I have a skimmer, two bottom supplies and three returns of which the Polaris runs off of one. I can control the flow to each return.

My pump appears to going. It used to get the filter up to 20lbs of pressure and now it is down around 10lb. It doesn't seem to be giving the Polaris the zip that it used too. It also appears to have a small leak somewhere. Since it is 4-5 years old and I also think that 1 3/4 HP is overkill on my pool, I was considering getting a new pump.

I like to run the filter 6 hrs / day in the summer spread out throughout the day.

Any suggestions on a pump that would be recommendable in my setup? Price is a consideration, but I am interested in enery efficiency as well. Do I need a two stage?

 

[JohnT]

I'd bet against your issue being a bad pump. They seldom just slow down like that. It is hugely oversized and your filter is way undersized for that pump, although the filter is probably fine for your pool I'd spend some time trying to figure out what the issue is before you start changing things. Where is the leak you are seeing?

 

[keithw]

Just a slight pooling of water under the pump. I agree with you that the pump probably just needs a looking at. I was going to tear it apart and check it out. But I keep coming back to the thought that it is way too big anyways. I must be burning up electricity running the darn thing. Forgot to mention that any pump I get would need to be self priming.

 

[spishex]

Any pool filter pump you find will be self priming. The only non self-priming pump you'll typically see around a pool is a booster pump.

You might have some debris in your impeller or something along those lines, but I'd also take a close look at your filter.

To do two turnovers in 6 hours for 6,000 gallons you only need 33 1/3 gpm. To effectively backwash your filter you need ~ 26.5 gpm. It will be pretty hard not to meet those criteria. The problem is trying to run the 280 at the same time. Do you have a booster pump for this or does it run off the filter pump?

 

[keithw]

The 280 runs off of the same pump. I can regulate the flow to all three of my returns so I normally throttle down the other two so that the one that the Polaris is hooked up to has more flow.

 

[spishex]

Well, you'll need to make a decision. You're supposed to have about 30 PSI at the 280 for it to run well. You could get away with a 3/4 or 1 hp pump for your filter, but that wouldn't do the trick for the 280. So:

- Downsize the filter pump and add a booster pump.
- Downsize the filter pump and get a Polaris 360 instead of the 280.
- Keep the pump you have now.

Regardless, take a look at your filter and impeller and see if you can spot any issues because as was said, an electric motor doesn't usually just slow down.

 

[keithw]

Geez, I incorrectly typed. I do have the 360. I was mistaken. I have the one designed to operate off of a standard return.

 

[spishex]

Ok, so you'll just have to be careful how low you go. Short of using a flow meter or a vacuum pressure gauge you'll just have to guess. What % of your water flow would you say you have to direct to the 360 to make it work well?

 

[keithw]

It operates on a pretty low flow. I would say that half of the normal "full" flow of the current oump seems to power it just fine. It could probably get by with less.

 

[spishex]

What Make/Model pump do you have and how many Sq Ft is your sand filter? Here's a very unscientific example of how to size your new pump if we assume you have a max rated super pump and a 2.0 sq ft filter, and that the performance of your cleaner can give us a rough estimate of your flow rate.

The minimum for a 360 is 15 gpm. If you can get by with less than half, let's call it 1/3 of your current flow that's required for the cleaner. This will let us unscientifically assume you are getting about 45 gpm from your system. With a 1-1/2 HP super pump that would put you at about 55' total head.

You still need enough power to run the 360 and backwash the filter, so let's say 30 gpm will be required. If you're running 55' @ 45 GPM then at 30 GPM you'll be down to 25' TDH. 25' @ 30 GPM = 1/2 HP Super Pump.

 

[keithw]

My filter is a Hayward S180T 18" sand filter and the pump was an Astral pump bundled with an 18" sand filter. I guess what I am asking is if I get a new pump, what brand one be creommended? Hayward has lot of different series and Pentair has a few as well.