New Pool: Which New Plaster Start-Up Method?

[TexasPool128]

I took these readings today:
FC 3
CC 0
pH 8.2
TA 100
CH 370
CYA 40

Since the pH was high again, & the CH went up 20ppm since yesterday, I went ahead & added 44oz. of MA. After I did, I read that I might not should have. I was concerned w/the CH @ 370 but I read since it's a new pool, that's normal. I was also concerned the pH was 8.2 again, up from 7.6 yesterday even though yesterday I added 20oz. of MA.
Did I do the right thing by adding 44oz.. of MA to bring down CH & pH or did I screw up?

 

[kimkats]

The acid will not do anything to the CH. The only way to lower CH is to add rain water or drain and refill some of the pool water.

Muriatic acid works on pH and TA only so you did the right thing adding it to lower the pH. Just keep an eye on the TA as you don't want it to come down too far.

Kim

 

[TexasPool128]

The acid will not do anything to the CH. The only way to lower CH is to add rain water or drain and refill some of the pool water.


Kim

It is supposed to rain for the next 10 days so that should do it!
I read if your pH is high & CH is high then adding acid will safely lower both of them. I guess that wasn't correct.

 

[ajw22]

It is supposed to rain for the next 10 days so that should do it!
I read if your pH is high & CH is high then adding acid will safely lower both of them. I guess that wasn't correct.

Acid will lower pH & TA, not CH.

 

[TexasPool128]

I found what I had read and clearly I misunderstood it. It says:
“To decrease calcium hardness, you must partially drain the vessel and refill it with lower-hardness water. Unless pH and alkalinity are already low, however, it will often be more practical to adjust the Saturation Index by lowering these two factors through the addition of acid than to replace water. This would certainly be the case where drought has caused limits to be placed on water used for recreation.”

 

[kimkats]

Ahhhhh I can see how you would get it confused! Good job finding what lead you astray!

 

[TexasPool128]

Numbers from this morning:
FC4.5
CC.5
pH 8.4
TA90
CH390
CYA40
I added 23oz of MA to correct pH. The CH is rising everyday so that has me a bit concerned but the plaster is only 11 days old.
Question:
Should I be concerned with the CH?
Thanks!

 

[kimkats]

It is very normal for pH and CH to rise as the plaster cures. It should slow down with time. How much time?? That depends on MANY different variables so it is no worry.

 

[TexasPool128]

Good to hear! I’ve been having to add MA every day.
Just how high should the CH get before I have to drain some water?

 

[ajw22]

Good to hear! I’ve been having to add MA every day.
Just how high should the CH get before I have to drain some water?

CH can be managed up to around 800. You are well away from problems.

 

[TexasPool128]

PoolMath says to add 19oz and Taylor treatment guide says to add 137oz. Why such a difference and which should I follow?
FC5.5
CC0
pH8.2 (12 drops to get to 7.6)
TA70
CH370
CYA40

I have a daily pH of >8.2 and can’t figure out why. I add MA daily, always what PoolMath recommends.

 

[ajw22]

What strength MA?

 

[TexasPool128]

What strength MA? PH 8.2 to 7.6 with TA 70 PM says 85oz of 31%.

View attachment 99880

31%.
Here’s a screenshot of my PoolMath app on my iPhone:

Why are ours so different?!?

 

[TexasPool128]

Using that version of PoolMath, I get 15oz. How’d you get 85oz?

 

[ajw22]

Never mind. It was my default borate setting that meesed me up.

So what pH level is the Taylor recommendation starting from for its MA dose? The Taylor 12 drops is calculating a pH higher then 8.2.

I would follow PM discipline and adjust for 8.2 multiple times until you get your p.h into the 7s. Too much opportunity for error with one big dose of MA.

 

[TexasPool128]

Taylor only goes to 10 drops. At 10 drops it says 137.28oz.
That’s a HUGE difference!

 

[ajw22]

Yes. And Taylor is assuming a very high pH. I don’t think PM is very accurate in the Effects of Adding Chemicals at those doses. If you believe it then your pH is over 10.

Take it slow.

 

[TexasPool128]

Thanks so much! I just saw your pool is 20x50. Dang that's a big pool!

 

[ajw22]

Thanks so much! I just saw your pool is 20x50. Dang that's a big pool!

It came with the house. The prior owner, a divorced wife of a sports star, spared no expense spending his money supporting his kids.

 

[Houston_TX]

We are at the same point. Filled up today, in Frisco.

I was at work when they kicked off but PB said they added acid but no CL yet.

Question, did you just circ pumps or are they still filling with water, overflowing into P trap. I came home and the water was overflowing. Turned it off but didn’t know if they expected to flush all the water and acid down the drain over the next day or so.

Hey Frac, did you post a build pic thread?