Since day one we noticed the spa overflow slowing down to a crawl towards the end of it's 8 hour cycle. Our contractor told us it was due to a dirty filter. So all summer I was cleaning the filter like every two weeks. It was not 100% dirty. But it was pretty dirty cause we get a lot of sand in our pool as we are in the windy ca desert. So I just went with it cleaning it every two weeks or so. Well, at the end of summer some rabid dogs got into our pool equipment and chewed up a bunch of stuff. The line from our 03 system was destroyed. So at the time I just disconnected the 03 and went all chlorine. Once I did that we NEVER has the spa overflow slow down again. Went 6 months without cleaning the filter etc.

Fast forward to a few weeks ago and I finally got the parts to repair the 03 system. I hooked it all back up and wouldn't you know it the spa overflow started slowing down again! But this time I noticed something I hadn't before this little window in the system was not full of water but air and bubbles. I know this line goes to the spa. And I am assuming that the bubbles from the 03 are getting trapped in it forcing the water to go to the pool more and less to the spa? When I restart the system this window fills up with water, but over time the bubbles collect and the spa overflow slows again. Can anyone explain what this little window is for?


Fast forward to a few weeks ago and I finally got the parts to repair the 03 system. I hooked it all back up and wouldn't you know it the spa overflow started slowing down again! But this time I noticed something I hadn't before this little window in the system was not full of water but air and bubbles. I know this line goes to the spa. And I am assuming that the bubbles from the 03 are getting trapped in it forcing the water to go to the pool more and less to the spa? When I restart the system this window fills up with water, but over time the bubbles collect and the spa overflow slows again. Can anyone explain what this little window is for?
