Looking for new filter, need help and advice

[vinnie]

I have a 20' x 50' rectangular pool. It has an old Hayward Bump filter that is way oversized. My plumbing is only 1 1/2". I have a Hayward 1.5HP pump. Pool has two pipes for suction two for return. Been researching pluses and minus on filters and leaning towards Pentair Quad DE 100. This will give me a large filter that will use a combo of cartridge and DE. Just want to make sure that my pump can handle this and that i'm making the right choice.

Thanks

 

[JasonLion]

The Pentair Quad DE 100 is a great filter and should work well with the rest of your system.

In general it is best to get an oversized filter and an undersized pump. A large filter is more efficient and can go longer between backwash/cleanings. A smaller pump saves electricity.

 

[Guest]

A smaller pump also increases the filtering ability of the filter by the reduced flow rate! (Just mare sure it's not TOO small!)

 

[vinnie]

I get confused so if someone can help me here I'd really appreciate it.

When it comes to GPM's. In my current setup i've been told by someone on the forum that I'm probably getting only 65 GPM's. Yet on the Pentair website the Quad DE 100 shows a GPM rate of 160. A guy at my local pool supply store told me that the 160 is the GPM that I need for the filter to work properly and to be able to turn the water over in an 8 hour period. Is this correct? Is the filter not going to work since I have such a low GPM?

Thanks for your help!

 

[chem geek]

If your pool has an average depth of 4-1/2 feet, then it's around 34,000 gallons in size. An 8 hour turnover would require a flow rate of 34,000/8/60 = 71 GPM, not 160 GPM. The 160 GPM rating on the filter is the MAXIMUM flow rate, not the required flow rate. Did I guess your pool's volume or depth correctly?

 

[MikeInTN]

The 65 GPM is probably the flow rate of your pump with associated piping, etc. The 160 GPM listed for the filter you're looking at is the max flow rate for that filter, meaning don't get a ginormous pump that will push over 160GPM through the filter, or you'll risk damaging it. You'll be OK with your pump and this filter, I'm pretty sure.

 

[JasonLion]

Lower flow rates are actually better for the filter, the filter will filter more throughly. The listed flow rate is the maximum, as others have already stated.

 

[vinnie]

I wish I knew just how many gallons were in my pool. Just bought the house last year right at pool closing time. So I don't know too much and its my first time owning a pool. I do know that the pool is 20' x 50'. I know that there is a diving board and I think the depth on that end is 8 to 8 1/2 ' deep. I think the low end is like 3' or so. People i've talked to said that it's around 46-48k. I would love to hear that it was below 40k because my other problem is i'm looking for a salt generator and pretty much all of them only go up to 40k.

 

[JasonLion]

Depending on various assumptions, I get volumes between 40,000 and 45,000 gallons. If you take some additional measurements, exact water depth in the deep end and the shallow end, how long the deep and is, how long the shallow end is, how long the slope between them is, we could come up with a more precise estimate. In any case, it is very likely to be above 40,000 gallons, but not by all that much.

Depending on your pump run time, peak summer temperatures, peak bather load, and how much you mind adding a little extra chlorine manually, you will most likely be fine with a SWG rated for 40,000 gallons. Long pump run times, lower peak temperatures, lower bather load, and willingness to add chlorine manually all allow you to use a smaller SWG.

By the by, the Pool Pilot Soft-Touch and Digital models, with the SC-60 manifold, are both rated for 50,000 gallons.

 

[vinnie]

yeah the Autopilot digital is the one i've been looking at.

 

[vinnie]

Had some emails back and forth with Pentair regarding the filter, here is what they've had to say so far



question:

LOOKING FOR RECOMENDATION FOR A FILTER. I HAVE A 46K GALLON POOL WITH 1 1/2 PLUMBING. I\'M TOLD THAT MOST LIKELY MY GPM IS AROUND 60 - 65. I\'M INTERESTED IN THE QUAD DE 100 BUT WOULD THAT WORK OK WITH MY LOW GPM?

answer:

It will filter fine, but you won’t be able to backwash, so you will need to take the top off and wash the DE of with a hose. The largest you can use and be able to backwash is the Quad DE 60

question:

Would that Quad DE 100 be the smartest choice

answer:

If you are comfortable with cleaning the filter manually it would be a good choice. You probably would only have to do that a couple of times a season because the cartridge DE has a longer cycle time than a grid DE, and when you oversize it adds to the cycle time. Cycle time being the time between cleaning