Calcium at spa spillway

Jun 27, 2012
48
Austin, TX
I have a small line of calcium buildup where the water spills over from the spa to the pool. It seems to have happened over the winter. I tried using a pool brush and that seemed to remove quite a bit of it but I was wondering if anyone know a better way to do it? It's on a flagstone surface btw.
 
It seems my biggest culprit is the PH that keeps rising. I keep adding acid to bring it down but it creeps back up again fairly quickly. The rest seems to be in line. Need to add about 50ppm to get CH to 250 although that seems a bit strange since I have deposits outide of the pool. Thanks for the advice on how to clean it!
 
So, that puts your CSI at 0.33 not enough to scale but enough to leave calcium when it evaporates.

Here is what I would target
PH 7.6 to 7.8
TA 60
CH 350

Adding 50 ppm of borates will lower CSI further.
 
We have been slowly lowering the TA recommendation over time. We are finding that in certain pools and conditions that PH stabilizes better and rises less with lower TA. Especially in saltwater pools but also in bleach pools. My TA is currently 50 and my PH is more stable than it has ever been. Quite a few contributing members have TA lowered to 50-60 range with favorable results.

With lower TA you should find that your PH rises less. If you find that your PH is less stable and bounces around then you can raise it back up a little.

Here is the latest recommended levels, Pool School - Recommended Levels
 
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.