Added Borate and TA went up

[Guillaume]

Hi there,

Last week, I've got my liner changed and filled the pool with fresh city water. I then balanced the water and got to here:
FC 3.0 ; pH 7.6 ; TA 90 ; CYA 20-25

I then added borate, for the first time: 589oz of Borate (9 boxes) and 2 gallons of Muriatic acid 31.4%, into my 10,000 gals pool, and left the pump run for 48+ hours.
I didn't fully follow the instructions, since I added all the borate + half of the acid. Then brushed. Then added half of the acid. Whereas the procedure says to add half of both, brush and then the rest of both.

Today, after a week where I had to travel, I find the pH and TA really high:
FC 0.5
pH 8.4
TA 160
Borate: I don't have a test yet.
CYA 20-25 (came from 0.8 gals of stabilizer, which I thought would bring it to a bit more than that, but that's today's reading)

My issue is : I didn't read anywhere it was supposed to raise the TA.
Should I just add some acid to hopefully lower both pH and TA?

Other question: do you change you TF-100 kit or just refill when necessary? Mine will be 2 years old in June. I'm only out of CYA test.

Thanks!
Guillaume

 

[chiefwej]

After you add muriatic acid to get your pH down where it should be, see if you still need to lower the TA further. If so, it can still be done, but will be much harder with borates in there. You can and should buy a refill set for your test kit. If it’s two years old the reagents have expired and testing will not be accurate.

 

[Guillaume]

Thanks. I've ordered the refill. Should I split the addition of acid , or can I put all in one go?

 

[chiefwej]

No problem doing it all at once, as long as you pour a small stream in front of a return. Use pool math to calculate dosage. Add a bit less, test, then finish.

Why did you decide to borate the pool? Borates are generally only used for salt pools where there is constant pH rise. Although it doesn’t reduce the total amount of acid required, it does lengthen the time between additions, by buffering rapid pH change. With fill water (like mine) that is very high CH and TA, and in a desert with very high evaporation rates it serves a valuable purpose, but I don’t see that you have any of those factors.

 

[Guillaume]

After reading about Borates on TFP it seemed like a good idea. I've had several episodes of algae last 2 years, and this post said it would help: So you want to add borates to your pool--Why and How

Anyhow, I'm adding acid now.

Is it expected though that following the procedure would bring such a spike in TA? I'd like to know if I did something wrong?

 

[ping]

Using 20 Team Borax will raise both the pH and TA, the acid is then added to reduce both. You will have to keep adding acid until you get them back to where you want them. Adding boric acid prevents the rise in pH and TA.

Adding that large amount of Borax is a very large change in pH and TA at once and is the reason why it should have been split in half. The pH is well over 8.4 right now.

Did you only add half the calculated acid as of now? The TA is sitting right where it should be if only half of the calculated acid was added. If this is true slowly add the other half of acid now.

 

[Guillaume]

Not yet, I only had 3lbs leftover dry acid, which is less than 1/3 of what's needed.
According to PoolMath, I need 207oz by weight of dry acid, and I've put in less than 64oz.

I've added that, will retest and will go buy 1 or 2 gallons of Muriatic acid.

 

[chiefwej]

Using dry acid for this process has added a lot of sulfur to the pool, as it is generally sodium bisulfate. Muriatic acid is preferred, as it adds no extra, unwanted chemicals to the water. Unless you have a pool that uses very little acid, stay away from dry acids.

Use MA to get the pH back in line then post up a full set of tests.

 

[Guillaume]

OK will do! I'll go to the store a bit later this afternoon. How long after putting the acid should I wait to test?

 

[ping]

After adding the MA give the pool a brushing and test in 30 minutes.

 

[Guillaume]

OK, put in 128 oz of Muriatic Acid, brushed, waited 30 minutes and just got the results.

FC: 0
pH: 6.9
TA: 80
CYA: 20-25

BTW I know what happened when I put the Borax in. I didn't get the right MA from Home Depot, I got the "Klean" one and it wasn't effective. I spent 45 minutes with them tonight to locate the MA which was still on its palette.
Tonight I knew it was the right one because of the fumes, which I had to run away from. How do you guys handle it?

What next? Aerating to increase the pH? Or soda ash?

Thanks for your help as always here

 

[ping]

Aerate, that will prevent the TA from rising.

 

[Guillaume]

Hey, so after aerating for 4 or 5 hours yesterday pH went up to 7.1 from 6.9. We're continuing today... thanks for the help again!

Again, I bought the wrong MA initially at Home Depot... my bad but maybe I'm not the only one in this case.