1. ## Rapid pH rise

I've been neglecting pH the last couple of months, but am currently trying to tame it. It was about 8.3, and I added a gallon of acid on Saturday morning and got it down to 7.5. It rose the next day (yesterday) to 7.8, so I put another gallon and got it down to 6.8. This morning I checked again and it was already up to 7.3. My TA started at 140 and is now down to 110. Should I just keep putting in a gallon a day until TA is down to about 60, and maybe then I'll see it balance a bit so I'm not putting in a gallon per day of 31.75 percent muriatic acid?

Today's numbers:

FC = 9
CC = 0
pH = 7.3
TA = 110
CYA = 25 (I just added 4 pounds of CYA yesterday, as it went from 50 to 0 over the winter).
CH = 450

2. ## Re: Rapid pH rise

You should use PoolMath to calculate how much acid is needed to lower the pH to 7-7.2 ... not lower than that.

As the TA drops, the rate of pH rise should lower.

3. ## Re: Rapid pH rise

Use poolmath and target 7.2 pH each time. If you go overboard on the acid, the pH gets too low, and you risk etching metal parts and weakening the plaster holding your pebbletec onto the gunite.

Since you have the symptom of rapidly rising pH, you're a good candidate for Lowering TA. Run the spa full tilt and let it spill into the pool. There's your aeration.

4. ## Re: Rapid pH rise

My TA was 100 last year and pH always climbed (my pool has fountains and thus plenty of aeration). Then I would add acid to bring it to 7.2, then aerate to raise the pH back up, then add more acid down to 7.2. After quite a few cycles of this, my TA is now 60, and pH seems to be pretty stable at 7.8.

5. ## Re: Rapid pH rise

I have an aerator fountain, so I can get aeration with a simple turn of a valve. I will just keep driving it down to 7.2 and let it rise, and push it down again until TA gets to be about 60. Richard, as for the danger of it being at 6.8, since it started at 6.8 and rose to 7.3 in less then 12 hours, my guess is it was at a "sub 7.0" level for just two or three hours at most.

In a related matter, here is what 4 pounds of CYA granules in two knee-high nylon stockings look like hanging from an empty chlorine dispenser.

11165273_10206831802940049_7727325821899305196_n.jpg

6. ## Re: Rapid pH rise

Excellent picture. I'm stealing it for reference.

7. ## Re: Rapid pH rise

LOL! Good one!

8. ## Re: Rapid pH rise

Anyone else picturing a bull? ... I will show myself out

9. ## Re: Rapid pH rise

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