Sand Filter Pressure Problems; Sand Bad in 3 MONTHS of USE?

[MikeInMo]

I wasn't there when the pool builder put the sand in but even with the other issues I have with them I just can't see any company putting in the wrong sand. Could be wrong but don't think that is it.

The filter is also doing a poor job of filtering now as well and the pool is starting to show it.

Your comment about the waste line might explain bleed down issue. It wasn't until they actually closed the pool last year that they finally put one of those blue rubber waste hoses on; before that I just had 3' of 2" pipe that sent water all over my pad. (The blue roll up hose connected on to that 3' pvc pipe.)

Any additional ideas?

[CarlD]

If you already know your builder cut corners, he might well have used sand-blasting sand because it's cheaper. Even at its cheapest ($5 for 5#) your filter sand costs $95. At its most expensive, it's something like $225.

It wouldn't be the first time.

[waste]

Mike, welcome to the forum!

Pop the top dome off (with the system off) and reach down and feel the sand, run your fingers through it - it should be nice and fluffy (wear a long sleve shirt to prevent fiberglass splinters in your forearm). You may just have a layer of 'crud' on the top of the sand, which needs to be broken up, or scooped out, if this is the case turn the multiport to rinse when you refire the pump to wash the stuff out.

What do you mean when you say "backwash" - the numbers you're giving indicate that you might not be doing it correctly - tell us what you're doing and we'll 'tweek' anything you might be doing wrong/ missing.

Again, welcome - we'll get you through this better than the pool store or Pentair!

[Sumo1]

Our church pool has four TR140 sand filters. The sand hasn't been changed in at least 15 years and does a great job. However, we replace the spider gaskets in the multiports each year. They're about $15. The multiport is a Triton model SM 20-3. We've had problems with people not pushing the handle ALL the way down before moving it. This seems to wear out the spider gasket faster. Hope this helps.
Hal
P.S. Someone told me always backwash three times. Don't know if that's just for a DE filter or if it's just hogwash but it's served me well so far.

[matt4x4]

My take on this is as follows:
10 lbs innitial fresh start up pressure sounds right, filter until 22 lbs and backwash to get 15-16 lbs - also sounds right - sand has now settled into place and is compacted to provide better filtration - thus 15lbs compared to 10lbs.
turn on system this year, filter never drops below 20 lbs - my guess here is you need a new guage - that's all, everything else is working as it should IMO unless you did not drain the filter over the winter and your laterals broke.
If you're not getting sand returned into your pool, your laterals are likely ok, and your sand is likely of the proper type.
Install a new guage (only 10 bucks) and report back - this seems to be a normal part of the whole process that continually gets overlooked and is the thing that breaks most frequently. (esp. if left out over the winter - most remove the guage and store it indoors)

[MikeInMo]

Well I switched out the gauge and the new one shows my pressure at the 15-16 range, right where I expected to be. The old one was showing 20-21 as I pulled it to replace it with the new one.

The simplest answers are usually the one that end up being right...but only if I have discarded them and then headed full force down the wrong path.

[Sumo1]

[QUOTE=MikeInMo;47601]
The filter is also doing a poor job of filtering now as well and the pool is starting to show it.


Since you've figured out the gauge problem, how's the water?
Hal