Pressure dropping while shocking???

[ouachita]

I'm in the process of shocking which I have done before. I installed a new gauge this year. It has been showing about 10 PSI but the pressure is going down. When I backwash it returns to 10 PSI. Today when I went to backwash it was 5 and returned to 10??? There are no air bubbles or leaks that I see. The system including the Hayward sand filter are going into their fourth season.

I must be going crazy from the shocking and brushing. Could it be a bad gauge?

 

[JohnT]

What does your pump strainer basket look like? Does the pressure return to normal if you just turn the pump off for a few minutes and turn it back on?

 

[duraleigh]

You have a restriction (maybe a clog) somewhere between the skimmer and the pump. Find that and everything will return to normal.

The gauge could be bad but not likely from your description.

 

[jblizzle]

My thought was a suction blockage as well, but then I could not think why backwashing would return to a higher pressure :?:

 

[ouachita]

I will check those things. What's strange is it's going down slowly. It took it 2 days to go from 10 to 5. I backwashed 4 hours ago and it's still at 10. I'll check the system out and report back this evening.

 

[duraleigh]

Are your skimmers clear of debris?

 

[ouachita]

Yes. And both skimmers are pulling water like they always have been. I can't tell about the main drain. The filter basket was not bad either. It's still at 10-11 right now. I guess I'll just see what happens this go round.

 

[duraleigh]

If your flow is normal then the thing that is abnormal is your gauge. I have never heard of one doing as you describe but if there is nothing wrong with your flow, it has to be the gauge.

 

[ouachita]

It did it again. 10 psi dropped to 5. Then back to 10 after backwash. The pressure drops to 0 as it should when the pump is off. Guess ill replace it.