3 days of rain and filter pressure

[lasercomp]

Hello,
I live in NY and we had about 3 days of constant rain. My pool water rose almost to the top of the skimmer. I felt it was a good opportunity to backwash the filter while removing some water. After backwashing until glass was clear, I stopped the pump and then rinsed for around a minute until the water was at the level I wanted. After putting the lever on Filter, my pressure was about 15psi. That is around where it was before doing the backwash. Is that a good amount of pressure for normal operation?

I tested my water after doing the backwash and had a PH of 7.7, FC of 11, No CC and CYA of 50. Did the CYA lower because of the extra water from the rainfall? Pool math says to add some stabilizer to bring CYA to 80. That should also lower my PH to hopefully the correct 7.5. I will stop chlorine generation so that my FC can go down. Thank you for the advice.

 

[Patrick_B]

Your Cya will lower some with a whole lot of rain, but have you had a whole lot? Where was the Cya before? Adding it won't lower your pH but I'm not sure that's what you mean to say. In your post it appears that way, but not sure just reading that. Your filter pressure may be normal there, and if you have a decent working gauge it's likely fine. Each setup is a little different. Do you know if the gauge is going to zero when the pump is off?

 

[lasercomp]

Thanks Patrick. My CYA was around 75 before it rained. Since I have a swg, I thought my CYA should remain at around 80. My gauge on filter looks like it works. It does go to zero when I turn it off.

 

[BoDarville]

After putting the lever on Filter, my pressure was about 15psi. That is around where it was before doing the backwash. Is that a good amount of pressure for normal operation?

The "normal" filter PSI will vary among pools and filters. It just so happens that my starting filter pressure after a backwash is 16 PSI which is very close to yours even though we have different types of pools. I would record your starting pressure and wait until it increases 25% (meaning your PSI will be ~ 19 PSI) before you backwash again.