Newbie Filter Question

[dj000524]

Just bought a house with inground 20000 gal. pool. Have been here for about a month and noticed a new issue that I am trying to figure out what is going on. After I backwash and rinse the filter I notice that the gauge reads around 16-20 on it. I have been told that is about what it should be reading. My question is the next day the gauge might be reading around 25-30. That seems high to me. After reading several posts I have seen that backwashing shouldnt been needed but maybe once every two weeks. But after 2-3 days the gauge is reading around 35 and bouncing almost to 40 and there is no cirruclation in the pool. After a backwash I can watch the water move around the pool. Once it gets high on the gauge theres not much water movement. I am beginning to believe that I have a partial clog somewhere underground. Anybody have an idea what it might be or have a solution. Thanks for taking time to read and replying.
DJ

 

[DaveNJ]

Add the specifics about your pool, size, kind, equip. to your signature. It help with answering your questions. Are you fighting algae bloom? Cleaning up algae will dirty a filter pretty fast.

 

[Hotrod30]

Can you see the backwash water as it comes out of the hose? When you first start to backwash, check the water to see how dirty it is.

 

[JasonLion]

Welcome to TFP!

If you have a DE filter it is time to open it up and do a complete cleaning, soak the grids in automatic dish detergent and clean up anything that has gotten stuck inside the filter.

If you have a sand filter, I can't think of anything that would cause the symptoms you describe.

 

[dj000524]

Ok thanks, guess I will need to open the filter up and see what I have. Kinda been not wanting to do that but gotta do what ya gotta do. After backwashing I noticed that the water did look clean. Also done a waste and the water looks clean also. I am just not sure what I need to do. Hate to call someone out for something so simple!

 

[duraleigh]

Even tho you can't see it (I assume), you could have algae in your pool. If you have enough chlorine in the pool to kill some but not all of it you could be in a continual cycle of washing dead algae out of your pool.

Assuming your water looks clear, a complete set of test numbers would tell us a little more about what's going on. My bet is on algae.

How are you chlorinating? When is the last time you tested the water?

 

[dj000524]

OK...Had a mustard algae issue but with chemicals and shock that was taken care of. Now on saturday I did a complete filter cleaning. Took filters out and washed down with strip kwik cleaner and water. Added more DE to the system and watched and the gauge started at 17. Had good suction with the skimmers and circulation with the jets. Now on Sunday evening the gauge on the filter was reading 25. Suction was ok but not great with the skimmers. Now Monday morning before I left for work I checked and the gauge is reading 30. This is really getting to be a pain. I am ready to close the pool for the winter and deal with this at the spring of next year. Could there be a partial blockage in the skimmer lines? I did do a 4 cycle backwash and rinse before I cleaned the filters Saturday.

22,000 gallon ig gunite pool
20x35
Pentair DE Filter

 

[duraleigh]

A blockage in your skimmer (suction) lines would result in a drop in pressure, not an increase, so that is not the issue.

It sounds to me like you have not broken the cycle of underchlorination.

Only a set of full test results will help solve that issue and eliminate the guesswork.

As you kill algae (with chlorine), it dies and gets pulled into the filter. The filter catches it but, in so doing, adds more resistance to the flow of water so your pressure increases.

This will very likely continue until you get all the organics (algae) cleared from you pool and chlorine (and lots of it) can do that best. Again, this in only an educated guess....we really need pool water test reults to help get your problem resolved.

Waiting 'til Spring is perhaps not a bad idea at this point but my guess is you'll need to address your chlorination issues all next summer unless you change the way you are sanitizing the pool.

 

[monkeywrench]

My DE filter when clean usually reads ~10. Even when I was fighting my alge bloom it took a few
days to hit near 20. You make short and minimal gains from cleaning. My guess is it it something in the return jet lines. Do you have anything else in the line between the filter and the jets. Heater,
clorinator,by-pass valves of any kind etc.? Certian types of valve might come apart internally and clog the passage.
Let us know about the complete set up. Maybe a photo or two

jb :monkey:

 

[dj000524]

Here are pics of my system that I can load.
My system was set up for the Polaris pool cleaner which has the other gauge on it.
I have more pics if that would help
[attachment=1:24njy02r]DSCN1298.JPG[/attachment:24njy02r]
[attachment=2:24njy02r]DSCN1302.JPG[/attachment:24njy02r]
[attachment=0:24njy02r]DSCN1307.JPG[/attachment:24njy02r]

 

[monkeywrench]

Its difficult to see all your plumbing connections from these angles. How about some shot at a wider angle from where the blue tarp is?
Do you have any water features of a heater as well?

You may want to use the valving to isolate the different lines and see if it has any affect on the pressure.

jb :monkey: