Lowering pH

[tcat]

Pool calculator keeps telling me to add 9 oz of MA to get my pH from 7.8 to 7.5... I "think" my pH is 7.7-7.8, but I've added at least 24 oz of MA (8 oz at a time) and color doesn't seem to change. All my other numbers are on target and pool is very clear. 31% Home Depot MA.

 

[linen]

What is your TA and Borate level (if you have added borates)?

 

[topher]

you introducing acid slowly? MA is heavier than water and doesn't mix that easy if not being stirred around. I pour mine VERY slowly in front of the return jet. and then usually brush some walls after wards. also how long are you waiting after before you check?

 

[RobbieH]

Is it possible you are over 8?

 

[tcat]

I could be over 8... I add slowly, try to make it a minute for 8 ounces (although that can be difficult). I don't add Borate and not tested for it. TA = 110
Still appears to be 7.8 with Taylor kit and with a test strip. Testing at least 12 hrs after.

 

[linen]

What is your FC level now?

 

[tcat]

5.0-5.5

 

[duraleigh]

pH changes, by their nature, are not always 100% predictable but if you add enough acid, it WILL go down....that's guaranteed. :lol:

7.8 is certainly in an acceptable range already but it sounds like yours may have been a little higher so good you are lowering it.

9 oz poured in front of a return could be put in quite a bit quicker....15 seconds is fine to let it dilute and disperse. the change should take affect within 30-60 min.

 

[ping]

It will be safe to check 1/2 hour after adding the acid and you can keep adjusting every 1/2 hour if you want to.

If you are actually not reading your pH high enough then the color change might not be noticable until until the pH drops below 7.6ish. When you get to the low 7's then you will see the yellowish color and it is a lot easier to read. It's the darker shades that take some time getting used to.

 

[tcat]

Happy to say it appears to be 7.5-7.6 after adding 12 more oz. Wish there was a "drop by drop" method for testing pH like the FC method.

Got to say thanks to everyone here. Been doing BBB (more like BA) for the past 4 weeks (since I dropped my $110 service), and have spent at most $12 in 4 weeks! (other than the water to get my CYA down to 50). Almost used one bottle of MA, and one 182 oz bottle of Clorox, that's it! I do run tabs for 1 in 4 weeks just to get rid of them, since it rained a lot and CYA got down to 35. Clear 84 degree water for the entire period (amazing what shade does for the Texas heat).

 

[RobbieH]

Congrats! You confirmed my suspicion, you were over 8 and it took more MA to lower your pH than you estimated.

Also, congrats for firing your pool service!