Adding Acid All at Once?

[tmarcoux]

Good morning!

I've been slowly getting my BBB pool into shape - moving one step at a time - and I'm at the final two steps of balancing my water (just needing tweaks). I'd like to get my TA down to @80, and that's my next step.

Here are the current readings:

CL = 5.5
CC = 0
TA = 100
pH = 7.8
CYA = 50
CH = 300
Salt = 2800
Temp = 79
Borates = 40

16,000g plaster pool with SWG and I'm using the TFP goals. To reduce the TA, Poolmath calculates 92oz of MA. My question: is there a danger in adding that much MA all at once? This is the most I've added in one dosing (due to the borates). Adding the Borates brought up my TA 20, and I'd like to get it under 80.

Once that's completed, thanks to this forum I will top off my CYA and I'm in simple maintenance mode.

 

[JasonLion]

You should not add all of that acid at one time. You don't want the PH to go below 7.2 at any point. Adding all of that acid at once is almost certain to lower the PH too much. Take a look at the how to lower TA article in Pool School for more information.

 

[tmarcoux]

According to Poolmath, that much acid will bring my pH down to 7.0. 66oz will bring it to 7.2

This is the guidelines from the how-to (7.0-7.2). I've been following this process before the borates and it worked out perfectly.

Since I suspect my pH is just a shade higher than 7.8, I went with the larger number, but I can split the difference.

Am I missing something??? I'm holding off until I am confident - as that is a lot of acid.

 

[JasonLion]

When doing large PH shifts Pool Math can be off a little. Don't add that much all at once. Add half or 2/3rds, give it time to mix in, test the PH and continue adjusting from there.

 

[tmarcoux]

That's the advice I was seeking! Thanks Jason!