Filter pressure increases 5 psi in 8 hours, normal?

[jcrewguy]

I've noticed the psi in our Hayward sand filter jumps from 12 to 17 when run for 8 hours. In years past I've never noticed this kind of increase in pressure. Prior to running the filter for 8 hours, I did vacuum the pool which had a little dirt spread throughout the bottom. My water is clear and the pool test is fairly normal. My pool pump does have a slight whine to it which it did not have at closing in October (thinking the ball bearings might be worn) but I don't know if that would have any effect on psi. Below are my recent pool test numbers. Any insight is appreciated.

FC - 6
CC - .4
PH - 7.4
Alk - 70
CH - 200

 

[Fingaling]

Backwash good and see if it goes down and stays down.

 

[jcrewguy]

I backwashed for 3 minutes and rinsed prior to vacuuming and running it for 8 hours this morning. Should I backwash again so soon?

 

[proavia]

From your pics, the water looks a little cloudy to me. You may be on the verge of an algae outbreak.

What is your CYA? That's the one you left out of the above test results. Without it, we can't tell if you really have enough FC. See the Pool School - Chlorine / CYA Chart

You may also want to consider - Deep Cleaning a Sand Filter

 

[jcrewguy]

CYA is 0-10.
I am adding stabilizer tomorrow to get it into the 30-50 range.

Also, the sand in the filter was replaced last season about midway through the summer (if that helps any)

 

[proavia]

Is the water truly cloudy - or is it just the pics? How does your water look today?
Has the FC been below the recommendations on the CYA/Chlorine chart?
What was the FC when you opened? And how did the water look?


You may want to do an OCLT to see how much FC you lose overnight - Pool School - Perform the Overnight FC Loss Test (OCLT)

 

[jcrewguy]

Forgot to mention in the initial post that if I turn the filter off for an hour and turn it back on, the psi goes back down to 12 again.

In the pics the water does look cloudy maybe due to the overcast day as well as the filter moving the water. When the water is still, you can clearly see the bottom, no cloudiness.

We just opened the pool a couple days ago so I'm slowly getting the numbers where they need to be. I never technically shocked the pool because the CC was less than .5 for the first time ever on opening. Should I still have shocked the pool?

The current FC level is higher than normal (6) according to the CYA chart since the CYA is currently 0-10.

 

[proavia]

Does the gauge go all the way to zero with the pump off?

Good - still water and clear to bottom. What were your numbers on opening - especially FC? Have you performed an OCLT? The OCLT would better determine if you needed to SLAM.

How much bleach (and what percentage) are you adding on a daily basis?