Sand filter pressure

[EmilyOTR]

So, my sand filter pressure is normally around 20 and I backwash when it gets around 25 or so. tonight I noticed my returns weren't working, my SWG said no flow and the pressure on the filter was at 30. I've never seen it that high. I backwashed 5 days ago, but it is May and pollen is falling like crazy. I backwashed, turned everything back on and returns are normal, SWG says flow is good but the pressure on the filter is around 28. what do I do?

 

[Texas Splash]

When did you open? Looking back at your Poolmath logs, the FC was quite low at one point. Did you open to a crystal clear pool, or did you have cloudiness/algae? Did you run a SLAM Process? Your spike in filter pressure is reminiscent of excessive organics.

 

[EmilyOTR]

I opened May 12, crystal clear, but green (due to a hole in my cover), but very low water level, after adding liquid chlorine and water, the pool was blue. I was planning to SLAM but when the color drastically changed, I just did an OCLT and passed.

 

[Texas Splash]

Oh, I remember that now. Well, even though the water transitioned to blue and you passed an OCLT, if the water wasn't crystal clear the SLAM may have been stopped too soon. You probably also have a tremendous amount of dead algae that sill needs to be filtered-out which would explain the quick rise in pressure. Pollen can cause some problems, but may not be 100% responsible for what you are experiencing. When was the last time you did a deep clean of the sand? Perhaps it's time for that as well?

 

[EmilyOTR]

I have never done that. I just looked it up, and while it doesn't look difficult, my pool is open. it says to do it while you are closed. I also don't open or close my pool, so I don't know a lot about that.

 

[Texas Splash]

It's good to do a sand deep clean at least every 2-3 years (IMO) to ensure the sand doesn't get compacted or channeled to a point that impedes proper filtering through the sand. It can be done at any time throughout the season. Those who close their pool each year do it at that time. The main issue some owners have is how the MPV is plumbed. Some installers glue everything to a point moving the MPV and PVC lines can be challenging. But some installers used unions which makes disconnecting easy.

 

[EmilyOTR]

I should say I personally don't open or close my pool, my pool does close every year. I just don't know what to do to start a deep clean. I don't want all that gunk going into my pool.

 

[EmilyOTR]

ok, weird - last night after backwashing it was at 30. I shut it off for the night. this morning when it came on, it was at 28. Now, about 1 hour later, it's at 25.

 

[Texas Splash]

last night after backwashing it was at 30. I shut it off for the night. this morning when it came on, it was at 28. Now, about 1 hour later, it's at 25.

Based on what was happening before that is odd. Perhaps your pressure gauge is bad? Some signs of a bad gauge are if it doesn't fall completely to zero when the pump is off, if it seems to stick in different places,, fluctuates a lot, or is leaking oil.

 

[EmilyOTR]

it does go to zero when it's off, it isn't leaking, and it doesn't fluctuate a lot....I mean, right now it's weird but I'm not sure I'd call this fluctuating a lot? it's down to about 23 now.

 

[EmilyOTR]

it's back to it's normal 20. it's just like it took longer after backwashing to go back to normal.