How much Acid with Bleach?

snazzy · Jan 17, 2014

I was wondering if anyone knows - all things being equal - how much acid (31.45%) you should have to add with bleach (8.25%) to keep the pH constant?

(important note: I don't mean to mix the two together as I prefer not to die from fumes or whatever) I just want to know how much I should be adding to my pool if nothing else is acting upon the pH other than the bleach.

Thanks!

Patrick_B · Jan 17, 2014

None, any pH change is temporary.

Isaac-1 · Jan 17, 2014

Acid requirement is completely separate from use of Chlorine, while high (over 10 ppm FC) Chlorine levels will skew the pH reading it is self adjusting when the FC level drops back down. Need for acid to adjust pH is varies considerably from pool to pool, factors that can effect it are type of pool (plaster or not), acidity of fill water, amount of aeration, acidity of wind blown dust, etc.

Ike

SwimAustin · Jan 17, 2014

When I used trichlor, my pH drifted down and when I switch to bleach, my pH drifts up. Which is to be expected. As Isaac says, you need to test both and adjust accordingly. Looking at my logs. I've used 5x as much 8.25% bleach as I've use 29% HCl by volume. That's fairly new plaster and my water and soil are alkaline, so things might be very different for you.

bobodaclown · Jan 17, 2014

It will truly depend on your pool conditions. You're daily chlorine usage will be much higher than your acid usage. That being said you may need to add chlorine every 3 days or so to maintain in a reasonable level you may have to add acid once or twice a month to bring the PH into check.
Measure, chart, then determine.

It will vary seasonally, and bather load.

Smykowski · Jan 17, 2014

In my case, nearly none.

Patrick_B · Jan 18, 2014

SwimAustin said:
When I used trichlor, my pH drifted down and when I switch to bleach, my pH drifts up. Which is to be expected. As Isaac says, you need to test both and adjust accordingly. Looking at my logs. I've used 5x as much 8.25% bleach as I've use 29% HCl by volume. That's fairly new plaster and my water and soil are alkaline, so things might be very different for you.

Any upward pH drift when adding bleach is temporary because the reaction of the chlorine conversion process winds up being a net neutral situation.

Test your pH first, adjust it if needed, wait 20 or more minutes, then add bleach and don't worry about it. Go about your routine and run the pH again tomorrow, or whenever that is usually, then start over. This really isn't something to be concerned about.