PH not responding much to muriatic acid

[nfusion770]

Alkalinity is between 280 and 300. I was going to try adding the muriatic acid/ aeration trick (homemade pvc aerator) but it doesnt seem to be working. My PH is always at the high end of the test kit even though I have not aerated in about a week- 7.8 to 8.0 or more. I added 190oz of muriatic acid per pool calc and it had virtually no effect on the test. 2 days ago I added another 190 oz and it may have brought it down to about 7.8. Since my test kit only goes up to 8 the ph could have been much higher I guess- hard to say. Anyway, should I just keep at it?

testing over the last week or so

CL 4-5
PH 7.8 or higher
TA 280 to 300
CYA finally up to about 40 from the 20s. I added a bunch so I will see where it is in a few days.
Salt level 3950- seems to be doing the trick but I might add another 50 pounds or so to bring it 4200.

Thanks for any advice.

 

[frogabog]

What brand of muriatic acid did you get? Does it happen to say "green" anywhere on the label? If so, you've got weak acid and it's a bear to calculate with it. The green stuff (only kind I can find around here) is ~25% instead of 31.45% so you'll want to verify you're using 31.45% if you're using the pool calculator to determine dosages.

And even so, the answer to your question is yes, yes, yes... keep at it. If you don't get the pH down with an acid addition, by all means add more, test and see if it moved. If not, do again till you see a result. You've got to put enough acid in to move the pH enough to be able to aerate to bring it back up, so you can do acid again. You've got a long way to go to get TA down. Lowering TA from 300 isn't easy, it's going to take a number of acid and aeration sequences.

 

[nfusion770]

What brand of muriatic acid did you get? Does it happen to say "green" anywhere on the label? If so, you've got weak acid and it's a bear to calculate with it. The green stuff (only kind I can find around here) is ~25% instead of 31.45% so you'll want to verify you're using 31.45% if you're using the pool calculator to determine dosages.

And even so, the answer to your question is yes, yes, yes... keep at it. If you don't get the pH down with an acid addition, by all means add more, test and see if it moved. If not, do again till you see a result. You've got to put enough acid in to move the pH enough to be able to aerate to bring it back up, so you can do acid again. You've got a long way to go to get TA down. Lowering TA from 300 isn't easy, it's going to take a number of acid and aeration sequences.

So simple yet such an eye opener. I never thought to check the concentration of muriatic acid. Thank you.

Most of this stuff is making so much sense now that I have a real pool, it is nice to find the answers to my questions fitting into my newbie conceptual framework.