Issues with Sand filter backwash pressure being high

[Nightshade]

Hello all,

I have done a search through the forums for this topic but have come up with nothing yet.

The problem I am having is with the sand filter. When filtering, it is going as high as 15psi indicating that it needs to be backwashed (normal PSI for my system is just over 10psi). When I backwash, it registers 35+ PSI.. Everything was working well yesterday. I opened the pool yesterday and had the pump on filter for about 8 hours. I was backwashing every few hours.. I then shut it down for the evening and today it seems out of whack.

Hayward 1hp Pump.
Hayward inline chlorinator
Jacuzzi Laser 225 Sand filter (4 - 5 years old)

Pool is octagonal, 10 foot sides, 6 feet deep in the middle, 4.5 feet deep around the sides.

Any suggestions before I crack open the sand filter and change the sand?

Joe

 

[JohnT]

Welcome to TFP.

36psi would indicate a complete blockage for most pumps. Is there a valve on your backwash line? Sometimes these are added as a fix for a leaky multiport gasket. Is the backwash line plumbed or is it a hose?

 

[Nightshade]

Welcome to TFP.

36psi would indicate a complete blockage for most pumps. Is there a valve on your backwash line? Sometimes these are added as a fix for a leaky multiport gasket. Is the backwash line plumbed or is it a hose?

Isn't blocked, there is water traveling out. it's traveling out a backwash hose.. which the pump has more than enough power to burst (as I found last year when the neighbour thought it would be fun to park on it when I was draining the pool..

there is no valve on the backwash line. I am going ot take the valve off and make sure everything is okay. this was working fine yesterday and today is acting up..

I did forget about it running last night till about 10pm when I turned it off.. pressure was high enough that I should have backwashed then.. I just hyper-chlorinated the pool yesterday as well.. ran it on the setting that skips the filter for most of the day just to get everything mixed in well..

 

[JohnT]

Does the flow have normal volume? What about if you set the valve to waste?

 

[Nightshade]

Does the flow have normal volume? What about if you set the valve to waste?

if i set it to whirlpool or filter, it is 12-15psi

if i set it to backwash, it is between 10 and 35.. eventually it settles at 30-35..

i pulled the valve off, pulled thepuece under it off and inspected the basket.. it appears to be attached via glue to the pipe that goes down so i couldnt remove that to see the sand and i didnt want to break any laterals.. there was no obvious obstruction..

edit:

found the issue.. squirrel or chipmunk decided it was good to store walnuts in the backwash hose.. i missed that one.. it was likely put into the hose last night.. little pests..

all sorted out now.. it is a good thing they are entertaining to watch or they would be dealt with harshly..

thanks again.. glad it was something simple..