How To Avoid Calcium Precipitation

[coutch]

Twice already I've had the issue where after a refill.

First time, I balanced the water (added metal sequestrant, raised the CH and TA, lowered PH until I had TA 85, CH 130, PH 7.6, all seemed fine. I then added Leisure Time PH Balance (not Plus). Label says not to use if CH is > 150, I'm @ 130 so I thought I was safe ... and Boom. as soon as I added it, the water got cloudy and I had precipitate everywhere. I got most of it to come out by making the water acidic for a few days, but in the end, drained and refilled.

Iused the same procedure, but instead used "silky smooth" from my local spa store, (their store brand). worked like a charm, no balance problem, PH stayed put (though I had a contamination issue when wife & friends used tub but didn't shock/sanitized afterwards, long story short, I did a decontamination before I refilled again

now on the next refill, the same thing happened ! I didn't use any PH balancer. All my variables were in the right range, I was adjusting the TA and adde 1/2 oz of baking soda (pool calc said 1 oz) When I went to check later that day, the tub was a calcified mess ... Gahhhh

fast forward today, I just refilled (My sanitizer will be Bromine in a floater)

TA : 30

PH 7.7

CH 40

From what I've read, I should:

1) raise the TA first, adding some baking soda, raising the PH at the same time ... target ~ 85

2) lower the PH with dry acid, target 7.5 - 7.6

3) raise the CH to ~130

I really want to make sure I don't get precipitation again, is that a good approach ?

[Dr. Spa]

Unless this is a spa/pool made of plaster/concrete/gunnite or has tile with grout, leave the CH where it is.

[mrwrick]

I wonder if this the advice I should follow. I have a 350 gal spa with bromine sanitization and a 24/7 DelOzone ozone generator. Water is clear. TA is 70-80, but pH is high (8) and CH is 60-70. Should I leave CH alone? Thanks Forum, always good advice here.