Son just added Acid instead of Bleach

PenskeFile

0
LifeTime Supporter
Jun 29, 2015
23
Georgetown
I have been transitioning my daily maintenance to my 13 year old son as he wanted to do more chores in order to increase his allowance. As he came in the back door this evening, I noticed he was carrying an acid jug instead of bleach. I learned of course that he had just poured 70 oz into the pool because he wasn't paying attention.

From PoolMath I am estimating this will lower my pH to about 6.2. It says that I should add 397 oz of Borax to raise the pH back to 7.6. There are some caveats on PoolMath however about pH changes being estimates, so I will need to let the water circulate and check in the morning.

So - any thoughts on what I should do to get this fixed? I added 25lbs of Boric acid a couple weeks ago, so my Borates are currently at about 40ppm. I'm worried about increasing the Borates too much and also what this will do to my Alkalinity which currently is about 100.

Should I go get some washing soda or soda ash instead? Any thoughts on the most cost-effective place to get these if that's the case?
 
:calm:
first thing is to take a test of the pH. It might not be as bad as you think. Do you have any way of getting the water to make bubbles? That will raise the pH without adding anything to your pool. Even pointing a return up and making it roll the surface of the water will help.
 
:calm:
first thing is to take a test of the pH. It might not be as bad as you think. Do you have any way of getting the water to make bubbles? That will raise the pH without adding anything to your pool. Even pointing a return up and making it roll the surface of the water.

I forgot about the aeration effect on pH and I do have a return from the spa to the pool as well as a "bubbler" on the tanning ledge. I guess I'll direct all the return volume to those tonight, run the pump through the night and then measure pH in the morning.
 
I would have thought the fumes would have caught his attention when he opened the jug!

No kidding, unfortunately he seems to sleep-walk his way through things that don't catch his fancy. I just had to march him back outside as he left the bleach jug, opened, sitting on the patio table. Oh, the joys of parenthood.

I also had forgotten that I have three "water arc" features that shot a jet of water about 5 feet in the air into the pool. I haven't used those in years and one is clogged, but I've got the other two shooting an arc that produces a good splash when it hits the pool
 
Interestingly, the pH measured this morning at 8.0. It was 7.6 two nights ago, which was the last time I measured. I can only suppose that the maximum aeration, combined with the pH buffering effects of the borates previously added help to keep the pH from dropping substantially when the acid was added.

I've turned off the aeration features and will take another reading this evening. Interesting result and not at all what I expected.
 
Last edited by a moderator:

Enjoying this content?

Support TFP with a donation.

Give Support
Did you test it last night after the MA addition, before aerating? Maybe he didn't put as much in as you thought.

A reminder that using the TFP method, testing before adjusting is always recommended.

I hear you on testing before adjusting. Keep in mind that it was 9:20PM and it was going to be at least 2 hours for the water to turn over before I could get an accurate test. I didn't consider aerating to be an adjustment since there is no way I know to quantify the effect.

So instead, I tested first thing in the morning (prior to adjusting) and lo and behold - not what I expected. So, no borates, washing soda went in - now it looks like more acid is needed!

He told me he added the acid to the same mark we add in bleach each night. About 70oz. I have no reason to assume thats not the case. I also tested the FC just to make sure that it wasn't simply that he was carrying the wrong jug. It measured 5.5 which is right where I wanted it.

And yes, before anyone mentions it - I store the acid way away from the bleach in my garage. It just so happened that there was an acid jug in that part of the garage because I was doing a periodic acid wash of the cartridge filters. He picked it up by mistake. I've noticed from some other internet searches that others have posted doing the same thing.
 
You shouldn't need to wait for one turnover of water to test the water. If you have decent circulation, then 30 minutes should be enough time for the chemicals to mix throughout the pool. Of course, if you are dosing at night and the pump isn't normally running you need to turn on the pump.

In fact, one easy way to test your circulation efficiency is to measure your FC level at several points around the pool, then add chlorine in one place over a single return flow with the pump running, then test the FC at your several points around the pool after 10, 20, and 30 minutes. You can use a 25 ml water sample for accuracy to within 0.2 ppm. You may find that even afte 10 minutes, most of the chemical is mixed, after 20 minutes all but a very small amount is mixed, and by 30 minutes you can't tell differences around your pool. Think of circulation is physical mixing in the pool itself. It really has nothing to do with turnovers of water (that is, water getting through the pump/filter), but rather that the pump is simply acting as an agitator/mixer of the water by pushing some out through the returns. Water does not have to ever get moved to the pump in order for that water to become mixed with other water in the pool.
 
Yes, aeration can offset the pH drop from acid addition. This is in fact what is done when trying to intentionally lower the TA. Also, at lower pH there is more carbon dioxide outgassing so even if one doesn't intentionally aerate the water the pH won't drop as much as you expect from acid addition if you wait too long to measure it.
 
I hear you on testing before adjusting. Keep in mind that it was 9:20PM and it was going to be at least 2 hours for the water to turn over before I could get an accurate test. I didn't consider aerating to be an adjustment since there is no way I know to quantify the effect.

So instead, I tested first thing in the morning (prior to adjusting) and lo and behold - not what I expected. So, no borates, washing soda went in - now it looks like more acid is needed!

He told me he added the acid to the same mark we add in bleach each night. About 70oz. I have no reason to assume thats not the case. I also tested the FC just to make sure that it wasn't simply that he was carrying the wrong jug. It measured 5.5 which is right where I wanted it.

And yes, before anyone mentions it - I store the acid way away from the bleach in my garage. It just so happened that there was an acid jug in that part of the garage because I was doing a periodic acid wash of the cartridge filters. He picked it up by mistake. I've noticed from some other internet searches that others have posted doing the same thing.

You store muritatic acid in your garage??? Not a good move generally considering how corrosive it is. It is stated that you can get significant metal weakening for things like garage doors etc.
 
we bought a shed specifically for pool chems at Lowe's for like $100.

Q. the pool is 12k. OP likes the chlorine at 5.5 ppm? or do i understand that wrong? and what's this about pouring bleach in every night? is that a manual thing i've heard about?? Just trying to learn here. 5.5 seems like a lot!
 
we bought a shed specifically for pool chems at Lowe's for like $100.

Q. the pool is 12k. OP likes the chlorine at 5.5 ppm? or do i understand that wrong? and what's this about pouring bleach in every night? is that a manual thing i've heard about?? Just trying to learn here. 5.5 seems like a lot!
Please start your own thread if you want to ask questions about the methods we use to maintain pools. Although I am surprised by these questions with your number of threads and posts.
Short version: The required FC level is a function of your CYA level according to the FC/CYA Chart. Yes, you need to add chlorine daily.
 

Enjoying this content?

Support TFP with a donation.

Give Support
Thread Status
Hello , This thread has been inactive for over 60 days. New postings here are unlikely to be seen or responded to by other members. For better visibility, consider Starting A New Thread.