I recently opened the pool with the help of a local pool company. Since opening, I have this issue where the pressure kept rising (25%+) over a 3-4 hr period and so I have been backwashing to get it back to a normal psi (generally around 14 psi at 3000 rpm). However, I have noticed since I opened that the water is not exiting to the street when I backwash; however it will start exiting to the street when I rinse (I have a 300 lb sand filter). I found out after the fact that the pool company put in some phosphorous remover and then read that those can have clarifiers which can cause clumping in the filter. After 5-6 backwashes, the pressure doesn't seem to be rising as fast so I am hoping that it has worked through the system, but I am concerned about the backwash not seeming to go to the street like it used to. Is it possible that the chemicals they put in are causing the filter to get clogged when it backwashes? Any recommendations?
Backwash not exiting drain
- Thread starter mariettapoolguy
- Start date
- Feb 6, 2015
- 6,393
- Pool Size
- 12300
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
Backwash and Rinse water exit the multiport thru the same opening.
Is it possible that the backwash time isn't long enough for the water to get to the street - but adding the rinse water provides enough volume that you see the flow at the street exit?
Does your multiport have a sight glass to monitor the water color/clarity?
Since the pressure in the filter is rising over a 3-4 hour period, suggest you do an Overnight Chlorine Loss Test.
If you fail the OCLT, then SLAM Process
What test kit are you using? Add it to your signature.
BTW - it isn't possible to read a CYA of 35 as the scale is logarithmic and not linear. Any reading between 30 and 40 is rounded up to 40.
Is it possible that the backwash time isn't long enough for the water to get to the street - but adding the rinse water provides enough volume that you see the flow at the street exit?
Does your multiport have a sight glass to monitor the water color/clarity?
Since the pressure in the filter is rising over a 3-4 hour period, suggest you do an Overnight Chlorine Loss Test.
If you fail the OCLT, then SLAM Process
What test kit are you using? Add it to your signature.
BTW - it isn't possible to read a CYA of 35 as the scale is logarithmic and not linear. Any reading between 30 and 40 is rounded up to 40.
Thanks, I did the test and only lost 0.5 PPM overnight. Based on that, my understanding is I passed the test, correct.
The multiport has the sight glass. It definitely clears up after a minute or so in backwash mode. That is when I switch to rinse.
I guess it is possible that there isn’t enough volume with the backwash. That said I usually have backwash run for at least a minute or two, while the rinse usually only runs for 30 seconds. I guess I could try a longer backwash, but in the past it didn’t take long to see it coming out to the street.
Yesterday, it took 11 hrs to see the pressure rise 25%, so maybe there was just some leftover junk in the pool or filter?
The water is not as crystal clear as I would expect, although i can definitely see to the bottom (it is just slightly hazy). I added some muriatic acid this morning as pH was above 8.
I am at loss for what to try next.
The multiport has the sight glass. It definitely clears up after a minute or so in backwash mode. That is when I switch to rinse.
I guess it is possible that there isn’t enough volume with the backwash. That said I usually have backwash run for at least a minute or two, while the rinse usually only runs for 30 seconds. I guess I could try a longer backwash, but in the past it didn’t take long to see it coming out to the street.
Yesterday, it took 11 hrs to see the pressure rise 25%, so maybe there was just some leftover junk in the pool or filter?
The water is not as crystal clear as I would expect, although i can definitely see to the bottom (it is just slightly hazy). I added some muriatic acid this morning as pH was above 8.
I am at loss for what to try next.
- Feb 6, 2015
- 6,393
- Pool Size
- 12300
- Surface
- Plaster
- Chlorine
- Salt Water Generator
- SWG Type
- CircuPool RJ-45 Plus
For the OCLT, was the pump running the entire time or did you let the pump run for at least 30 minutes prior to taking the after sunset and before sunrise tests? SWG off (or output set to 0%) during the entire OCLT?
Are you using a SpeedStir/SmartStir for your testing?
How are you testing for salt? Your SWG probably isn't working or working to its full potential with salt at only 2200 ppm. Additionally, with a CYA of 40, the FC will burn off pretty quick - consider raising CYA to 70.... after the water is totally clear and chems balanced.
What were the results of the CC test? It doesn't show in your PoolMath logs.
What manufacturer and model number of sand filter?
Have you done a deep clean of the filter?
Filter pressure rising 25% over 11 hours usually indicates a chemistry issue, not a filter issue.
With a TA of 210, your pH will continue to rise pretty quickly.
Consider working on lowering the TA.
www.troublefreepool.com
What is the pH, TA and CH of your fill water?
Are you using a SpeedStir/SmartStir for your testing?
How are you testing for salt? Your SWG probably isn't working or working to its full potential with salt at only 2200 ppm. Additionally, with a CYA of 40, the FC will burn off pretty quick - consider raising CYA to 70.... after the water is totally clear and chems balanced.
What were the results of the CC test? It doesn't show in your PoolMath logs.
What manufacturer and model number of sand filter?
Have you done a deep clean of the filter?
Filter pressure rising 25% over 11 hours usually indicates a chemistry issue, not a filter issue.
With a TA of 210, your pH will continue to rise pretty quickly.
Consider working on lowering the TA.
Lower Total Alkalinity
A lower Total Alkalinity level can help a pool owner stabalize their pH increase. We'll explain how to lower TA with a little help from muriatic acid.
www.troublefreepool.com
What is the pH, TA and CH of your fill water?
For the OCLT, was the pump running the entire time or did you let the pump run for at least 30 minutes prior to taking the after sunset and before sunrise tests? SWG off (or output set to 0%) during the entire OCLT?
Are you using a SpeedStir/SmartStir for your testing?
How are you testing for salt? Your SWG probably isn't working or working to its full potential with salt at only 2200 ppm. Additionally, with a CYA of 40, the FC will burn off pretty quick - consider raising CYA to 70.... after the water is totally clear and chems balanced.
What were the results of the CC test? It doesn't show in your PoolMath logs.
What manufacturer and model number of sand filter?
Have you done a deep clean of the filter?
Filter pressure rising 25% over 11 hours usually indicates a chemistry issue, not a filter issue.
With a TA of 210, your pH will continue to rise pretty quickly.
Consider working on lowering the TA.
Lower Total Alkalinity
A lower Total Alkalinity level can help a pool owner stabalize their pH increase. We'll explain how to lower TA with a little help from muriatic acid.
What is the pH, TA and CH of your fill water?
I followed the instructions having the pump running 30 min before sunset and before sunrise tests. SWG was off the entire time. I don't use a speedstir but do shake enough to make sure it is absorbed. I added salt twice over the last week, it is at 3600 PPM. After the OCLT test, I have had it running at 75% the last couple of days and FC rose from 4.5 to 8 so I am going to bring it down to 50%. CC test came back at 0 (I have since added it to my pool math app).
I have added the pump info to my signature. I have not done a deep cleaning on it. If it continues to be a problem that will be my next step.
That said, the pump doesn't seem to be rising in pressure as fast so it may be that the chemicals have cleaned up. The water is clear now.
I am going to add enough CH to the pool to get it to about 250 (fill water has very low CH). My understanding is that Calcium chloride is slightly acidic, so I am hopeful that will bring down the pH some and then help the TA decrease. If not, I will continue adding more muriatic acid and then aerate until TA drops down to the normal range. Thanks again for all your help!
Charlie
