Getting rid of scale

[asquare]

After following instructions from this forum, my pool is now balanced:
FC = 6
CC = 0
PH = 7.6
CH = 300
TA = 80
CYA = 40

I travel so I only test my pH once a week. I always adjust to 7.5 but the pH tends to grow to 8.0-8.1 over the week.

Question 1 = Short of adding Muriatic 2 or 3 times a week, is it ok to get my pH down to 7.3 so that it stays in the [7.3 - 7.8] range? Or is it better to be in the [7.5 - 8.0] range? I assume the former.

I have a spa that overflows into the pool. The water line goes down slightly when the pool pump is off, leaving a scale line on the tiles (see picture - I took the picture at noon so the actual situation is looking worse than on the picture).


The situation is stable since my pool got balanced, but I would like to get rid of the scale line. I read the following options
1) Pumice stone (and elbow grease)
2) Diluted muriatic acid (1:5 ratio) applied directly to the scale (need to pay attention to the grout)
3) Lower the pool pH level and brush frequently with stainless steel brush
4)

Sequesterant (e.g., from Leslie's pool)​

5) Sanding / grinding (overkill for my situation)
6) Acid wash (WAY overkill for my situation)

Question 2 = is the above the right sequence or would you suggest a different sequence?

Thanks!

 

[Richard320]

Aim for 7.2 pH and buy a little insurance.

As a side benefit, the TA will come down some. If the TA is in the 60 range, the pH rise should slow down some, which will buy you even more time between adjustments.

 

[asquare]

Thanks Richard - what's your perspective on removing the scale line?

 

[Richard320]

Thanks Richard - what's your perspective on removing the scale line?

Pumice stone to remove the worst. Adjust pH and TA to drive CSI negative, raise the water level, and be patient.

 

[asquare]

Will do and will report back in a few weeks - thanks!