Sand filter pressure

[dannyboy]

After running the pump and sand filter for several days the pressure
will rise from 10 to 20 psi.
The question is when I shut the pump off lets say 18 psi and restart the
pump the next day the pressure may start at 12 psi. It will then take several
hours or days to get back to 18 psi. The psi values vary but the up then
down cylce is continuious. Is this normal?
New Triton II TR100 filter new sand
2 inch pipe
2 HP wisperflow pump
Consistant after back wash pressure 10/11 psi
35k inground.

[Poconos]

Never saw a noticeable change when I was running just sand. Since adding a little DE I now see the pressure creep up a few PSI during the day. Shutting down overnight and restarting next day, pressure cycle sort of starts all over. My guess, and this is only a guess, is fine stuff (DE + fine crud in my case) gets packed on the sand surface and causes the pressure to slowly rise. Shutting off flow causes this stuff to go back into suspension and then takes time to settle on the sand surface again. Just an observation and I don't worry about it.
Al

[graciec]

I am noticing the similar thing.We have a jacuzzi sand filter .I did put 1-2 cups dim.earthtoday and pressure went from about 40-45 lbs,but last year it used to run around 25 before backwashing[no eath last year].
I backwashed today in 2 sessions but it is still not back to where it used to run last year.Why? thanks!

[Poconos]

If we get off the original topic too far I'll split things apart and make a separate thread. Graciec....40-45 seems like a really high pressure for a centrifugal pool pump, which they all are. I suspect your gauge may be way off.
Al

[graciec]

Al,now you've scared me!!!! What should I do? We no longer communicate w/ the place that sold us out stuff 2 years ago.
Is it a matter of resetting the gage?

[graciec]

OK now it's running closer to 50lbs and the gauge needle didn't go back down when I shut it off.Is it supposed to go back down to zero when it's shut off?? can't remember!
I checked the filter basket and it's fine. thanks for any help.