Is my sand filter sized right?

[TheGoose]

Update to my thread:

My 1-HP Pentair (motor) bit the dust this spring. I was running the pump intermittently, getting ready to do some pre-spring maintenance. I did not use the pump over the winter. It ran for a few days before crapping out.

I'm trying to decide whether to replace the motor only and keep the same pump, or change the pump/motor and filter back to DE.

Pool season doesn't start until late April/Early May so I have time to think.

What would you do?

[PoolDoc]

What would you do?

Depends.

1. Does the cost of a new pump & filter fit your budget? Or, do you need to minimize costs?
2. Does your piping need to be corrected, at the pump? (Send pictures of your current layout to poolforum@gmail.com)
3. Do you have a lot of debris land in your pool, so that your skimmer really needs to be running much of the time?
4. Does it matter to you (or your family) whether your pool is REALLY clear, or just clear. (Sand filters are lower maintenance, but lower clarity as well.)

[Watermom]

Sand filters may be slightly lower clarity, but for most people, I doubt that would be able to tell the difference. I have always had a sand filter and my water always appears extremely clear. Simple maintenance is hard to beat. Just my nickel's worth.

[TheGoose]

Budget is not a huge concern.

I don't think my piping has to be corrected much, if any. Small changes of course to re-route the plumbing but I'm plenty capable.

I do have lots of trees etc (from neighbors yard) hanging over my pool, but I kinda like the shade so it's a catch-22.

I had a DE filter once before. Changing out the DE about once a month is no big deal. Pulling apart the filter and cleaning once or twice a season also doesn't seem like a lot of work for the return. I wouldn't mind going back DE, I just want to make sure that I don't do all the work but still have murky water.

What size pump/DE filter would be appropriate for a 18,00-20,000 gallon pool?

I really like my water clear. It doesn't have to be crystal, but it seems that there is very little in-between. It either seems to be crystal clear, or murky. Not much in between.

[CarlD]

Isn't this a 325# sand filter? If so, there is NO WAY it's not sufficient for an 18,000 gallon pool. You just may have the wrong pump.

I think it's really time to explore your pool chemistry.

[TheGoose]

What pump do I need then?

[CarlD]

I can't think this late at night, but I find it hard to believe that ANY 1hp pump made is straining THIS filter! I'm thinking it's a chemistry or plumbing problem, not a filter/pump sizing problem. Fellow mods and senior contributors?

[PoolDoc]

Carl, the Whisperflo is a more efficient pump than average, so a 1HP WhisperFlo moves more water than a 1HP SuperPump. Plus, the Whisperflo is often sold full-rate, so you are comparing a 1HP full rate Whisperflo with 1HP uprate (=3/4HP full rate) SuperPump.

The give-away that this is almost certainly the problem is early in the thread, when Goose comments that he's

almost certain than when I backwash I am losing sand, and I noticed that when I changed the sand that the level was a little low.

Flow is high enough to push dirt through sand BEFORE it gets high enough to blow sand out of the filter during backwash.

Goose, since budget isn't a big issue, I'd recommend the following changes:

1. Replace the TA60 with a TA100 filter. That will allow flows up to 70 GPM without overloading your filter. However, better clarity and longer filter runs will come with LOWER flows.
2. Replace your motor with a 2 speed 1HP motor . . . and run on low almost all the time.

If you want a timer, Intermatic has one that will switch speeds. But, using a toggle switch may be all you need. With a 1HP Whisperflo and a TA100 you'll be running 20 - 30 GPM on low speed! You'll probably need high only to backwash and vacuum.

Alternatively, if you want optimize things to the max, you can go with a Pentair Intelliflo, which is a 2HP Whisperflo with special motor and variable speed drive. I believe it comes with a built-in timer.

HOWEVER, please send photos of your piping at the the pump and filter before you start, and let me or Mark (mas985) look at it before you do. There are a number of piping practices that many pool builders follow that are HORRENDOUSLY bad, hydraulically. Correcting these can greatly improve your efficiency.

Here are links:
2 speed motor (A1 Pool Parts)
WhisperFlo pump
Intelliflo (Whisperflo w/ VFD)
Tagelus filters