Just had new pool start up

[Titan7]

You want the TA at 60 with a pH of 7.8. PH rise will be much less and less acid will be needed.

The lower the TA, the higher the pH needs to be to compensate and vice versa. You can already see how the number effect one another.

Aeration does not lower TA, it raises the pH without also raising the TA (really the only way to do that). Acid lowers the pH and TA together. There is no way to lower the TA without also lowering the pH. If you can figure out a way to do that, water chemistry will be the least of your worries because you'll have more money than you can figure out how to spend.

Your white ring will disappear with a low CSI or I'll give you every dollar you've ever paid me back

CYA levels are based of sun exposure, not so much just SWGs. I know this stuff is confusing and contradictory but the recommended levels were created for a certain type of person in a certain climate which doesn't apply to all.

Thanks Brian and PoolDV, anytime you are in OC swing by for a couple cold ones.

I meant to say aeration raises PH. So I am thinking that each time I push PH down from 7.5 to 7.2 it's lowering TA a little more each time. At least that's want is seem to be doing based on the process.

I also see where your numbers of TA@ 60 and PH@ 7.8 came from, you set pool math SALT at 3500. I got my numbers based on the current salt level of 1000ppm.

So because I must be really slow on the uptake of this chemistry, when I have TA to 60PPM and [email protected], is the PH target now 7.8 vs (7.2-7.5) So I want to tightly regulate PH at 7.8 and TA at 60.

I plugged all my target numbers into pool math (after salt is added and CYA is at appropriate levels)

FC= 5
PH=7.8
TA= 60
CH=275
CYA=70
Salt=3500
CSI= -0.31

So this is the magic formula.

 

[bdavis466]

That's the formula until your CH rises. Mess with the numbers and throw 500 in there, then try 700, then 1000.

When your TA gets to 60, target a pH of 7.6-7.8 (lower to 7.5-7.6 when the pH rises above 7.8-7.9). Even better yet, adjust all of the numbers to maintain a CSI between 0 and -0.3.

 

[bdavis466]

The amount of acid to lower you pH from 7.5 down to 7.2 will lower your TA by 5.4. You can see why its such a slow process that gets exponentially slower (pH rise) as the TA level drops.

CSI is calculated on a logarithmic scale where all of the test results come in to play. This is why you see the experts here always saying You really can't give good advice without know all of the numbers and exactly why there isn't an "ideal" pH, TA, CH, and temperature.

 

[Titan7]

The amount of acid to lower you pH from 7.5 down to 7.2 will lower your TA by 5.4. You can see why its such a slow process that gets exponentially slower (pH rise) as the TA level drops.

CSI is calculated on a logarithmic scale where all of the test results come in to play. This is why you see the experts here always saying You really can't give good advice without know all of the numbers and exactly why there isn't an "ideal" pH, TA, CH, and temperature.

Thanks man. I will post all of them in a couple days when i run another CYa test.

Thanks foe the info on the TA drop with acid. So to drop 20 ppm, that will take a couple weeks. Again sorry for all the dumb questions, i really appreciate all the help from you and PoolDV

 

[bdavis466]

That's correct but the reason it takes so long to lower the TA is because the pH rise becomes so slow.

If you were to reach an equilibrium, aeration would have no effect on pH.

 

[Titan7]

That's correct but the reason it takes so long to lower the TA is because the pH rise becomes so slow.

If you were to reach an equilibrium, aeration would have no effect on pH.

Thx, i will just do the aeration on the weekend when we are using the pool. Hopefully i can get TA to 60 before i hit an equallibrium. Will post a full battery of test results later this week. Have a great week!

 

[bdavis466]

You won't ever hit it. The goal is to get as close as possible though. A TA at 50 and a pH of 7.8 is about as good as it gets

 

[kimkats]

You can turn you return eyeballs up so they roll the water good to help the PH go up. My cats hate when I do this LOL.

 

[Titan7]

Making progress
Fc-5
Ph-7.5
TA- dropped to 70
Ch-275
Csi= is -0.31@ ph of 7.5, and will drift up to -0.02 @ ph of 7.8. So CSI is in the 0 to -0.3 perfect range.

Should i keep dropping TA to 60 by dropping ph to 7.2 again, or now just let TA stay at 70 and keep ph in the 7.5 to 7.8 range. I have not added salt yet.

Thx

 

[bdavis466]

Add the salt. Your TA is fine right now

 

[Titan7]

TA went back up to 80 ppm. Ph is at 7.6-7.7 which gives a slightly Neg CSI. Should i go back to dropping ph down to 7.2 to bring TA down to 70 or leave it?

 

[bdavis466]

It's going to be a constant struggle since the fill water and plaster will contribute to TA rising. Keep an eye on the CSI and use that as the indication for what you need to do to the TA.

 

[Titan7]

TA now at 90 so its gone up from 70 -90 in 35 days. Still have a neg. CSI number. It took 5 days for ph to go from 7.5 to 7.7. Should i be trying to loer TA again by dropping ph to 7.2.

 

[bdavis466]

Focus more on the CSI than actual pH ACD TA targets. What is the CSI currently?

 

[Titan7]

Ph @ 7.7 (color just not exactly 7.8). CSI= -0.07. This is the current CSI.

Dropping ph to 7.5 will give a CSI of -0.26

Once ph hits 7.8 csi will go to 0.03

 

[bdavis466]

Time to lower the TA since you are nearly at 0 CSI.

 

[Titan7]

Lower ph to 7.2 correct? That will make csi -0.54

 

[bdavis466]

Yes, that's fine