Reducing TA - How long?

[red-beard]

FC 8, pH 8.0, TA 90, CYA 80, Borates 50, Salt 2900 as of 7 AM this morning. Poolmath says to add 1.5 gallons to reduce the pH to 7.0. Added!

I'm now "aerating". The question is, how long should this be? Lower Total Alkalinity - Trouble Free Pool just says to keep doing it until the pH reaches 7.6.

Also, is this enough Aerating?

 

[mknauss]

Sadly it takes as long as it takes. Hard to judge. Test pH every hour or so.

 

[red-beard]

Would I be better off connecting a hose with a sprayer to the submersible pump? I've never tried to lower TA before. Target is down 20 points, which is what Poolmath says 1.5 gallons of MA will do.

 

[mknauss]

More aeration the quicker it goes.

I don't see an issue with your water chemistry. Why are you pushing your TA lower? Your CSI is running pretty negative already.

 

[red-beard]

pH Stability. Just want to drop TA to about ~70. With pH 8.0, TA = 90, borates at 50 and CYA 80, my Carbonate Alkalinity should be ~57. I'd like to get it in the 30-40 region.

 

[mknauss]

OK -- I would add some calcium if you are pushing your TA down.

 

[red-beard]

Yep. I'll be adding CH up to 400

 

[red-beard]

Better Aeration

 

[red-beard]

Started with a pH of 6.9. This morning 7.3.

 

[red-beard]

Update. The pH has stabilized at 7.8. Very very happy with the results.

 

[Stoopalini]

Update. The pH has stabilized at 7.8. Very very happy with the results.

Being a month later, how has this been working out for you?

I'm a couple of hours north of you, in Central Texas, and am debating adding Borates to my pool to try and reduce the pH reading where the water settles. I already have my TA around 60 - 70, but my pH still rises fairly quickly (about 0.10 points every 12 hours), and settles around 8.1 at equilibrium.

I started a thread to discuss ways of controlling this, when Marty remembered your post and referred me to it

I'm wondering if I add 50ppm Borates to my pool, and keep my TA around 60 - 70 ... if that'll be enough to lower the carbonate alkalinity of my water to result in equilibrium occurring in the 7.8 or so range, instead of 8.1. This seems to be exactly what you did, and I'm hoping it's been stable for you.

 

[red-beard]

Adding the borates will increase your TA. You then reduce your TA which will reduce your CA.

pH is more stable. I need no more than 1 qt of MA a week now, when I used to add that every 2-3 days. So I went from a gallon every 10 days to a gallon a month. My TA is 70-80. So I could try to go lower.

 

[Stoopalini]

Adding the borates will increase your TA. You then reduce your TA which will reduce your CA.

pH is more stable. I need no more than 1 qt of MA a week now, when I used to add that every 2-3 days. So I went from a gallon every 10 days to a gallon a month. My TA is 70-80. So I could try to go lower.

Hmm, I didn't think Boric Acid would increase the TA ... did you use Borax and Muriatic acid to add your Borates?

I'm basing my understanding on This Further Reading Article




So adding the qt. of MA per week, are you able to keep the pH at 7.8 or below?

 

[red-beard]

I used boric acid. Borates are part of TA. Then you use MA to reduce TA and aeration to increase pH