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

[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.