Return lines getting blocked by SWG air bubbles

[EricJ320]

At the beginning of the season I installed a Circupool Edge 40. It’s been great once I got the settings and runtime dialed in. Other than testing the water I almost never have to think about the chlorine side of my pool maintenance. FC is almost always between 5 and 7 ppm, and CC is usually 0, and at most is 0.5 ppm after heavy use.

The one issue I’m seeing though is, on occasion, one or two of my three return lines stop flowing because I believe the air bubbles produced by the SWG somehow block the flow. I started noticing it when the strongest jet closest to the pump seemed to stop flowing. I then can run the pump momentarily up to full speed and the one running jet discharges lots of bubbles and agitates the water pretty aggressively, returns to normal, then all three jets function normally. To combat it I programmed the pump to run at a higher speed to start the day, hopefully to clear out any air left from the previous day. This has mostly worked, but I still have seen it later in the day from time to time.

Anything I can do to correct it? Am I running my pump too low? Am I way off base to the cause of the flow issue? Should I be concerned? No leaks noticed on the return side, and no bubbles pump from the supply side.

Thanks in advance for any advice.

 

[proavia]

Post you pump runtime and speed schedule.

 

[EricJ320]

2700 rpm from 7am-11am
1750 rpm from 11am-10pm
Polaris 360 runs everyday from 8:30am-10am
This time of year the SWG runs at 75% from 7:15am-9:45pm

 

[cowboycasey]

I do not think you have to run on high for 4 hours, 5 to 10 minutes should be fine.. It seems weird that bubbles stop the flow of water completely... could you run it for 10 minutes on high 2 or 3 times a day? That would get any air pockets created out of the pipes..

 

[Jimrahbe]

Eric,

In my tiny mind I can't see how the bubbles from a SWCG could clog up any return line...

If you put your hand in front of the return do you feel no water flow at all??

I run my pump at 1200 RPM and have plenty of SWCG bubbles, when the SWCG is generating, but it has never reduced the actual flow.. If I change the pump speed to say 2,000 RPM, I do get some larger bubbles and noise for about 10 seconds..

Show us a couple of pics of your equipment pad showing the cell and all the return lines.

Thanks,

Jim R.

 

[Brett S]

I agree that it seems very unusual that the SWG would cause this.

If this is repeatable and happens every day or nearly so, I’d suggest turning off your SWG for a day or two to see if it still happens. My guess is that it will. Obviously you’ll need to use liquid chlorine for that time so your FC level stays where it should.

Once we can confirm or eliminate the SWG as the cause then we can try to figure out how to stop this from happening.

 

[EricJ320]

I do not think you have to run on high for 4 hours, 5 to 10 minutes should be fine.. It seems weird that bubbles stop the flow of water completely... could you run it for 10 minutes on high 2 or 3 times a day? That would get any air pockets created out of the pipes..

Thanks Casey for the suggestions. One point worth noting, I don’t run it on higher rpm just for this issue, but also after running some math on the flow rate I was running it on high for a couple of hours to increase the amount of filtration I’m getting and to increase skimming. I just moved the higher rpm cycle to the start of the schedule to help clear any air. I’ve thought about your suggestion and would have done it already but I’m limited to 5 cycles per day, and the shortest a cycle can be is 2 hours. What I was able to do is adjust the priming sequence to start the day with 3 minutes at 2600, and then moved my higher cycle to later in the day, so at least it gets cleared out twice a day.

Eric,

In my tiny mind I can't see how the bubbles from a SWCG could clog up any return line...

If you put your hand in front of the return do you feel no water flow at all??

I run my pump at 1200 RPM and have plenty of SWCG bubbles, when the SWCG is generating, but it has never reduced the actual flow.. If I change the pump speed to say 2,000 RPM, I do get some larger bubbles and noise for about 10 seconds..

Show us a couple of pics of your equipment pad showing the cell and all the return lines.

Thanks,

Jim R.

Jim,
Thanks for your comments as well. Yeah, it has me baffled as well. And yes, the jets that stop seem to have zero flow coming out of them. Your experience of getting bubbles for 10 seconds when ramping up your rpm’s is exactly what I’m seeing, I just think it’s to a much larger degree, and somehow I believe it’s trapping air to a point it stops flow in the plumbing. The jet that remains flowing seems to have increased flow and lots more bubbles when flow is blocked from the other jets. I need to check my flow meter before and after I clear the air blockage to see if it’s still flowing the same amount of water, just through the single jet. Once I clear the air, sometimes manually by ramping up the rpms that flowing jet returns to a more normal flow rate and bubbles coming out decreases significantly. I’ll try to get some pictures to post, although I do think it’s also worth noting that we are on a sloping lot and my equipment pad is below all the jets and plumbing.

I agree that it seems very unusual that the SWG would cause this.

If this is repeatable and happens every day or nearly so, I’d suggest turning off your SWG for a day or two to see if it still happens. My guess is that it will. Obviously you’ll need to use liquid chlorine for that time so your FC level stays where it should.

Once we can confirm or eliminate the SWG as the cause then we can try to figure out how to stop this from happening.

Brett, thanks as well. I’m not closed off to the idea that it could be caused by something else completely, although, it didn’t do this before the SWG was installed. I do realize something else could have happened since then to cause it. We’ve only owned the house and pool for a year to the day, so I’m still learning about its original construction and more so it’s operation. I’ll try your suggestion to try to eliminate the SWG as the cause, my only concern is I haven’t been able to figure out when it’s going to occur, it’s not a constant issue and difficult to replicate it, so it might be tough to know when it will happen, if at all, when the SWG has been turned off.

 

[mgtfp]

Does your pump have an option to define a separate priming time and rpm? My pump lets me do that and each time it is turned on, it runs for 10min on higher rpm. I don't really need that for priming, my pump always stays primed, but it also drives out excess gas from the returns without having to "waste" a normal cycle for that.

 

[mgtfp]

Sounds like you have an air lock:

Air lock - Wikipedia

en.wikipedia.org

 

[EricJ320]

Sounds like you have an air lock:

Air lock - Wikipedia

en.wikipedia.org

I tend to agree with you that I’m getting an airlock due to the physical layout of the plumbing.

My pump does have a priming function, and I did amend the setting to accomplish a blow out at the start of the day, and I moved my higher rpm cycle back to the middle of the day to give it a midday blow out as well. If I broke up the cycles and had a stop time in between so that the priming function would clear any air out at the beginning of each cycle I think I’d run out of cycles pretty quickly, as it counts stop times as a cycle. I’ll run it like I have it now for a few days and see how it works to keep things flowing.

Thanks again to everyone for their help!