Pressure gauge will not move

[miller9951]

I have a 26" sand filter and I just replaced the pressure gauge on it because I thought it was bad but today when I was backwashing to waste I took notice that I had a lot more pressure. When filter was in normal mode and I held my hand over the return jet I could barely feel any pressure so I backwashed the filter and after that I had a lot of pressure. I was told and from what I have read on here that I should not backwash my filter until the pressure reads at least 8 psi more than it does after a fresh backwashing. My new gauge has not moved at all it was still reading 5 psi. I did try putting the old gauge back in and I got the same reading. Do you think that I may be dealing with a bad gauge or could I be dealing with some other problem?

Thanks,
Eddie

 

[JohnT]

That's a large sand filter for an AG pool. Not that that's bad. If you have a small pump (which you should), you may have very little back pressure. You might just have to backwash when you notice a reduced flow. That's what I do.

 

[miller9951]

Hey John

Thanks for the reply. When I seen the size of that filter on my receipt I also thought that didn’t sound right so I went out and measured it and the receipt is correct. The motor is a two speed motor and the only thing I could see was a sticker that said 2.5 hp which I am assuming is the fast speed. I am not sure what the hp is at the regular speed setting. I am going to look again tonight when I get home to see if I can see any other stickers on the motor.

Thanks again,
Eddie

 

[JasonLion]

A 2.5 HP dual speed pump will be just under 1/3 HP on low speed. Low speed is about right for your pool. High speed, which is way more than that pool needs, would show an obvious difference on the pressure gauge between clean and dirty.