Pool pump and filter pushing de and filtered material back into inground swimming pool for about 60 seconds upon startup and the pressure gauge drops back down to the same as after backwashing. Pentair FNS Plus 60 fiberglass DE filter. It's doing this even with new O-rings in the valve handle assembly and new filter grids. Valve handle is in down position. Filter pressure is at 10 lb with new de, and it starts this problem at about 15 to 17 lb, after which it drops back down to 10 lb as if it's starting all over again.
Backwash into pool when pump starts
- Thread starter ronaldray
- Start date
- Jul 21, 2013
- 65,062
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Welcome to TFP.
Show us your complete equipment pad.
Which pipe is the pump attached to?
Show us your complete equipment pad.
Which pipe is the pump attached to?
Attach pictures. Originally the plumbing was set up for a second pump applying pressure to Polaris pool vacuum that worked on pressure instead of suction. But that plumbing was capped off and I now use a suction vacuum. Also most of the suction from the main drain has been closed off for years. I didn't have this problem during the winter months when the water was cold around 55° Fahrenheit water temperature. But the outside daytime high temperature now is up around 75° F. And the algae in the pool is growing along with my Landscaping and Lawn around the house during the last month LOL
Attachments
I normally backwash about once every 2 weeks during the summer months when the outside air temperature is 100° Fahrenheit. And when I backwash, I also take the clamp off of the filter and remove the top cap and hose off the grids inside, and I drain off any residual de in the bottom of the filter canister. Is it possible for the de material to pass through the filter grids if I am running too much pressure on the pool vacuum? The pool vacuum climbs the walls better with more pressure.
- Jul 21, 2013
- 65,062
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
- Jul 21, 2013
- 65,062
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
You should follow the SLAM Process for your pool while you solve your filter problems.
www.troublefreepool.com
Algae Archives
www.troublefreepool.com
- Jul 21, 2013
- 65,062
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Check that you have the internal air bleed assembly and filter screen in place....
www.troublefreepool.com
www.inyopools.com
www.inyopools.com
Internal air bleeder assembly - Do I need it?
I have a Pentair Sta-Rite PLM150 filter. It has an 'air bleeder assembly' which is internal to the filter housing. This is not the same component that is used to bleed air from the housing when turning the pump on, nor is the pressure gauge screwed into this assembly. The filtered water flows...
www.troublefreepool.com
Pentair FNS Plus Internal Air Bleed Assembly - 59023600 - INYOPools.com
Pentair FNS Plus Air Bleed Assembly
www.inyopools.com
Pentair FNS Plus Internal Air Bleed Assembly - 59023600 - INYOPools.com
Pentair FNS Plus Air Bleed Assembly
www.inyopools.com
Last edited:
Thank you so much for this great information. I think that my slide valve assembly is installed properly, and has new O-rings. So I'm kind of suspecting that air bleed assembly on the top of the manifold.
I see where it is recommended to backwash after the pressure increases by 25%. In the past I have used the rule of thumb to backwash when the pressure increases by 10 lb. So if I started at 10 lb, then I would backwash when it gets up to 20 lb. But if I use this 25% rule, then I would be back washing when the pressure increases from 10 lb to 12.5 lb. I think that would require a lot of De changes and of course the extra expense of all that extra de. Your thoughts please?
I see where it is recommended to backwash after the pressure increases by 25%. In the past I have used the rule of thumb to backwash when the pressure increases by 10 lb. So if I started at 10 lb, then I would backwash when it gets up to 20 lb. But if I use this 25% rule, then I would be back washing when the pressure increases from 10 lb to 12.5 lb. I think that would require a lot of De changes and of course the extra expense of all that extra de. Your thoughts please?
- Jul 21, 2013
- 65,062
- Pool Size
- 35000
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- Pentair Intellichlor IC-60
Every pool is different. You have to learn what works best in your pool.
I have a spa spillover and can see when it slows to a dribble. That is my visual indication that the filter is getting clogged and needs to be backwashed. For me, that is about a 33% PSI rise.
As your filter loads up the flow will decrease at your normal pump RPM. This does not work if you are running a VS pump in a GPM setting.
Find what in your pool is an indication of decreased flow and use that.
It's for me usually the speed of the pool vacuum. Thanks much for your great advice!
Here's what the inside grids look like with the cap off of the canister after backwashing and before additional washing with the hose. No clogging on the internal air bleed assembly screen or tube, but it's possible the back washing cleaned it off?
Attachments
I think I found the solution! One of the filter grids stitching came loose enough at the bottom of the grid pipe enough for me to put my little finger in. Would this have been big enough to push so much of the d e and filtered material back into the pool Jets?
I also went ahead and purchased a new set of grids called First Choice, a brand used by a local dealer. So I'm not sure if it was the opening in the stitching of the grid that came with the filter, or if the original grids were all leaking de material.
After running the filter for 6 hours, all of the green algae was gone and I could see the main drain again, and the next day when I turned the filter on, there was no de and filter material being blown back into the pool Jets.
I also went ahead and purchased a new set of grids called First Choice, a brand used by a local dealer. So I'm not sure if it was the opening in the stitching of the grid that came with the filter, or if the original grids were all leaking de material.
After running the filter for 6 hours, all of the green algae was gone and I could see the main drain again, and the next day when I turned the filter on, there was no de and filter material being blown back into the pool Jets.
