Filter Pressure Increases After Backwashing

TFO · Postby **TFO** » Tue 26 May, 2009 20:25

I have a Hayward Pro series sand filter that's less than a year old. After opening the pool this past weekend, I found the filter starts at around 17 psi with a strong jet stream, but within an hour and a half, the pressure is up to 23 psi and the stream is very weak. After backwashing, the pressure drops down and the process starts all over again. Although my water is chemically balanced and super-chlorinated, it is still light green and cloudy with about 8 inches of visibility. My filter's pressure never went much beyond 17 psi last season. Any help is appreciated. I feel like I'm just wasting money on electricity at this point.

Postby **Denali** » Wed 27 May, 2009 00:37

TFO wrote:I have a Hayward Pro series sand filter that's less than a year old. After opening the pool this past weekend, I found the filter starts at around 17 psi with a strong jet stream, but within an hour and a half, the pressure is up to 23 psi and the stream is very weak. After backwashing, the pressure drops down and the process starts all over again. Although my water is chemically balanced and super-chlorinated, it is still light green and cloudy with about 8 inches of visibility. My filter's pressure never went much beyond 17 psi last season. Any help is appreciated. I feel like I'm just wasting money on electricity at this point.

Hi,

With only 8 inches of visibility something is going on in the pool. Perhaps it is all dead algae which will plug a filter up pretty quickly.

If you're confident that the chemical balance is correct and you're dealing with dead algae, add a clarifier and when the debris settles to the bottom, vacuum to waste.

A look inside the filter might be a good idea also. Look for channeling in the sand that would allow dirty water to go back into the pool.

When I hear light green I think copper. If it's been tested for copper and it's fine then not to worry.

Hope something here helps.

Good luck.

Postby **mr_clean** » Sun 31 May, 2009 11:28

it happens because of all the algae in the pool being filtered & will keep doing it until it is all gone.

any filter gauge that is dealing with a green algae filled pool will go up in a short amount of time as this is where all the algae is being caught.

mwilliams · Postby **mwilliams** » Sun 31 May, 2009 21:56

I am actually searching this site for an answer on pretty much the exact issue. I have a Hayward filter as well and last year had no issues. This year when I vacuum or backwash the pressure starts at around 10 PSI and quickly climbs to 25PSI. If I stop the pump and move back to filter and come back the pressure returns to 10PSI.
I too have water with poor clarity - I have changed my sand and the issue continues. Any help is appreciated.

Devildawg88 · Postby **Devildawg88** » Sun 25 Jul, 2021 20:58

Would this be true with a DE filter as well? I just drained pool to acid was it and the pool is cloudy and light green. The filter has been completely cleaned and backwash again a few days later because the psi is going to 35. I'm also having poor to little pressure in my return side. Very frustrated!

Denniswiseman · Postby **Denniswiseman** » Mon 26 Jul, 2021 01:50

The filter is doing it's job
You need to Slam (Shock Level and Maintain) with relation to Chlorine / CYA Chart and Recommended Pool Levels