Pool was filled about 2 1/2 months ago. I've been managing the chemistry.
CL - 4
CC - 0 (sometimes 0.5)
PH - 7.5 (I let it rise to 7.8 then add acid to lower it to 7.5)
CYA - 30 (I'll raise it when it gets spring time)
TA - 80 (been 80 for a while. was a high of 100 right after PB balanced the water following fill)
CH - 325 (rock steady)
What do you think the white deposits are? They are ONLY on the spillway of the spa. Spa has been heated and used 4 or 5 times since fill.
I tried a 10:1 dilution of MA. Splashed it on with a cup and tried brushing with the pool brush on one spot. It got a little milky and some of it came off. Some of it appears pretty dang hard. Continued splashing with 10:1 dilution and brushing made no progress.
What should I try next?