Bubbles coming from returns when SWG is on

[dloki]

I've had the SWG turned off for the past week and a half during my SLAM process, now that it's over I turned the SWG back on at 25%. Tonight I noticed tiny bubbles coming from the returns in the with the pool light on, small enough that I initially thought they were debris passing through the sand filter. I can validate that the bubbles only appear when the SWG is turned on, if I turn it off within 30 seconds the bubbles stop and if I turn it back on within 30-45 seconds the bubbles start again. Is this normal for a SWG or is it an indication of a bigger problem? The SWG was installed last year.

FC - 7
CC - 0
PH - 7.6
CYA - 65 (added more this week and waiting a week before adding more for a target of 75)
TA - 90
CH - 100

 

[JamesW]

Normal. The cell makes hydrogen gas as a byproduct.

 

[dloki]

Ok, thanks.