Hello again. Spent quite a bit of time here back when the pool was new about 5-6 years ago, and am needing some assistance again. 
Several years ago we had white scaling begin to appear on the waterline tile just below and around our spa waterfall. We figured it looked like calcium buildup and worked with muriatic acid and pumice stone to try to remove it. Last year we had someone come out from a pool tile cleaning company to remove it, which they did. Now, it's returning. About the only thing we can use that will remove it is a flathead screwdriver. This isn't found anywhere around the pool, other than around this waterfall from the spa.
So, now I'm needing some assistance to remedy this. The answer may be staring me in the face, but I'm not the expert that many of you are. Here's my current numbers:
FC 5
pH 7.4
CYA 50
TA 90
CH 190
After seeing the CH, which is low, I wanted to ask opinions before making any large scale changes.
Thanks!
Several years ago we had white scaling begin to appear on the waterline tile just below and around our spa waterfall. We figured it looked like calcium buildup and worked with muriatic acid and pumice stone to try to remove it. Last year we had someone come out from a pool tile cleaning company to remove it, which they did. Now, it's returning. About the only thing we can use that will remove it is a flathead screwdriver. This isn't found anywhere around the pool, other than around this waterfall from the spa.
So, now I'm needing some assistance to remedy this. The answer may be staring me in the face, but I'm not the expert that many of you are. Here's my current numbers:
FC 5
pH 7.4
CYA 50
TA 90
CH 190
After seeing the CH, which is low, I wanted to ask opinions before making any large scale changes.
Thanks!
