Need some advice for using Muriatic Acid

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FailedChemistry

FailedChemistry

Active member
Jul 4, 2013
30
St Louis, Missouri
Pool Size
11813
Surface
Plaster
Chlorine
Liquid Chlorine
So i'd like to get my PH levels down from somewhere north of 8.2 to a nice 7.5

Went to Lowes today and bought a jug of 31.45% 20' baume muriatic acid. But i must admit, i'm a bit intimidated by it. Actually terrified is probably more accurate.
My username is no mere exaggeration. Literally the only thing i remember from chemistry is "Do what you otter, add acid to water." So i'm assuming that's important.
But i really want to conquer this pool stuff, so i need help.

Please feel free to respond as though you're talking to a 4 year old. Assume zero working knowledge.
i'm nervous about this acid and don't want to overlook anything.

Pool School says:
"Muriatic acid should be added to the pool by pouring slowly in front of a return jet with the pump running. You should pour slowly enough that pouring an entire jug takes more than two minutes. Leave the pump running for at least 30 minutes after adding muriatic acid."​

1. So, is that straight out of the jug?
Someone else here at some point wrote about diluting it in a bucket of water first. i'm curious which is best?

Also, poolcaculator is very specific about me adding 22oz of muriatic acid.
i bought a little plastic bucket at the hardware store with graduated markings on the side indicating ounces, so i could more easily measure out 22oz.
2. Is plastic safe?
Should i have looked for a specific type of plastic or something?

3. I'm confused about the relationship between TA and PH.
If TA buffers changes to PH, do i need to change the TA somehow before i try to change the PH?

4. How about storage? Will muriatic acid be safe in my basement? How long will it last?

This morning's test:

FC 2
CC .5
TA 140
CH 270
CYA 80
PH more than 8.2

My FC is low, It just finished raining... i'll get to that after i get the PH right. Or should i add chlorine first?
And i know my CYA is high. But i just got it down from 100 this week. (small victories)
 
1. So, is that straight out of the jug? Yes. You could mix it, but that's one more pour and one more opportunity to splash and leave tiny holes in your favorite T-shirt. I tend to first dip the jug in the pool in case there's any dribbles on the bottom of it. I have a nice ring etched in the aged concrete from that once upon a time. Then I just kneel down and lean out and pour the acid into the measuring cup and then intop the pool in front of the return. The closer you are to the surface, the less time the acid has to get away and attack you!

2. Is plastic safe? Yes. Much safer than glass, and metal will dissolve. I use an acrylic cup. It's lasted three years so far. If the cup is that flexible plastic like tupperware or the bleach jug, it's even better.

FC is low, It just finished raining... i'll get to that after i get the PH right. Or should i add chlorine first?
And i know my CYA is high. But i just got it down from 100 this week. (small victories)[/QUOTE]

You can adjust either one first. Just allow half an hour or so with the pump running for it to mix before you add the next chemical.
 
Muriatic is just fine to deal with if you use some common sense. Keep it downwind away from your nose, the fumes are powerful. Set the jug down by the edge of the pool right above a running return. Remove the cap and seal.

Lower the jug down into the water so the spout is only maybe 4-5 inches out of the water and the rest of the jug is submerged. This will make it lightweight and it won't splash.

Pour in about 1/6 of the contents...that should be around 20 ounces...close enough. lift the jug out of the water, set it on the deck and put the cap back on.

Done. Didn't even get your hands wet.

Test pH about 30 minutes to an hour after you dose. Adjust if necessary.

If you spill some on yourself, just dilute immediately by sticking you hand (or whatever) in the pool.....your skin may not even turn red unless you panic and run around with it on you.

EDIT: This is almost identical to Richard320's post but I'll leave it anyway.

Keep your questions coming slowly. Solve your pH problem and then go to the others but stay in this thread.
 
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^^^you're getting good advice. Don't be afraid. And when you've successfully learned to take care of your pool by testing and balancing your own water, I'd say that is a pass for chemistry........maybe?
 
That was fast!
I was going to sit back and use my waiting for an answer as an excuse to delay opening that scary jug.
It felt like a bomb waiting for me down there.

Thank you so much for your help. And for going into so much detail!
Your replies have boosted my confidence. I'm totally going to go do it right now.
 
I usually take a 5 gallon bucket and fill it 3/4 with water then add my chemicals to the water in the bucket (I just pour them into the bucket slowly from my measuring cup) and walk the perimeter of the pool pouring the water/chemical mix into the pool slowly... I try to not add more that ~48oz of any particular chemical to 3/4 of a bucket so if you have to add a lot of bleach (EX: when shocking the pool) just make a couple passes...

Muriatic Acid has a near indefinite shelf life, just keep it off the ground and stored upright and away from Bleach (I keep mine in the garage opposite the bleach for the pool). There are a few variants that you can buy at the hardware store or pool store... There is the pool specific stuff 15% MA which is overpriced and takes 2x the acid to achieve the same results as regular MA, the low fume/odor stuff (strength varies but usually 15% and may contain chemicals you don't want in your pool) and as my father always used to say "The fully leaded stuff" which is just plain 31% Muriatic Acid... Save money and buy the plain 31% which is usually from the paint section of the hardware store with the cleaning chemicals

TA controls Ph Drift in your pool (Ex how fast your Ph rises or lowers over time naturally)... The higher your TA the faster your Ph can change... You shouldn't make any changes to your TA before adjusting the Ph as the calculations for how much Acid or Base to add to adjust the Ph rely on the alkalinity not changing...

There are two things that are really important when adding any chemicals to the pool...

1.) Always add chems to water and not the other way around (water to chems can lead to an exothermic reaction and cause stuff to flash boil and spray you in the face or worse...)
2.) Be very careful mixing Bleach and Muriatic Acid... Rinse your bucket and measuring cups *every time* you switch chemicals... I usually just dunk the bucket in the pool 1-2 times followed by my measuring cups... Bleach + MA = Poison Gas...

I use one of THESE from Lowes to measure chemicals... You can also use a glass measuring cup but I tend to avoid glass around the pool... (Again rinse everything between uses)

Muriatic acid is not something you want to get in your eyes, you should probably avoid breathing the fumes and definitely don't drink the stuff but otherwise is fairly safe. Its definitely not like the acid you see in the movies.... You do want to treat it with respect as it will stain concrete and clothing and the fumes might catch you off guard the first time... Its a good idea to be a little extra cautious so pour slowly and stand back a bit... Having splashed myself directly in the eye with the stuff you should definitely wear some sort of eye protection...

I will say that my experience with MA reaches far beyond taking care of my pool. When I was younger I used to use MA to clean holds at a rock climbing gym... The concentrations we used varied from 5-1 to straight up 31% MA. The stuff is strong and the fumes suck but not so strong that its going to cause severe burns or anything like that. It will definitely wake you up in the morning if you have any cuts on your hands or get any in your eyes...

If you do get some on you don't panic. Just rinse off and you'll be fine...
 
I added 4 gallons a few weeks ago! Every once in awhile it would hit me in the nose. Pour slow and you'll be fine! Once you do it once you'll be confidant enough to do it again when needed. :goodjob:
 

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JVTrain said:
Love this tip. Will do next time I have to add.
Click to expand...

Just make certain you don't let the mouth of the jug dip below the water surface, or let water splash back in the jug.

Ghost68 said:
I usually take a 5 gallon bucket and fill it 3/4 with water then add my chemicals to the water in the bucket (I just pour them into the bucket slowly from my measuring cup) and walk the perimeter of the pool pouring the water/chemical mix into the pool slowly... I try to not add more that ~48oz of any particular chemical to 3/4 of a bucket so if you have to add a lot of bleach (EX: when shocking the pool) just make a couple passes...

Muriatic Acid has a near indefinite shelf life, just keep it off the ground and stored upright and away from Bleach (I keep mine in the garage opposite the bleach for the pool). There are a few variants that you can buy at the hardware store or pool store... There is the pool specific stuff 15% MA which is overpriced and takes 2x the acid to achieve the same results as regular MA, the low fume/odor stuff (strength varies but usually 15% and may contain chemicals you don't want in your pool) and as my father always used to say "The fully leaded stuff" which is just plain 31% Muriatic Acid... Save money and buy the plain 31% which is usually from the paint section of the hardware store with the cleaning chemicals

TA controls Ph Drift in your pool (Ex how fast your Ph rises or lowers over time naturally)... The higher your TA the faster your Ph can change... You shouldn't make any changes to your TA before adjusting the Ph as the calculations for how much Acid or Base to add to adjust the Ph rely on the alkalinity not changing...

There are two things that are really important when adding any chemicals to the pool...

1.) Always add chems to water and not the other way around (water to chems can lead to an exothermic reaction and cause stuff to flash boil and spray you in the face or worse...)
2.) Be very careful mixing Bleach and Muriatic Acid... Rinse your bucket and measuring cups *every time* you switch chemicals... I usually just dunk the bucket in the pool 1-2 times followed by my measuring cups... Bleach + MA = Poison Gas...

I use one of THESE from Lowes to measure chemicals... You can also use a glass measuring cup but I tend to avoid glass around the pool... (Again rinse everything between uses)

Muriatic acid is not something you want to get in your eyes, you should probably avoid breathing the fumes and definitely don't drink the stuff but otherwise is fairly safe. Its definitely not like the acid you see in the movies.... You do want to treat it with respect as it will stain concrete and clothing and the fumes might catch you off guard the first time... Its a good idea to be a little extra cautious so pour slowly and stand back a bit... Having splashed myself directly in the eye with the stuff you should definitely wear some sort of eye protection...

I will say that my experience with MA reaches far beyond taking care of my pool. When I was younger I used to use MA to clean holds at a rock climbing gym... The concentrations we used varied from 5-1 to straight up 31% MA. The stuff is strong and the fumes suck but not so strong that its going to cause severe burns or anything like that. It will definitely wake you up in the morning if you have any cuts on your hands or get any in your eyes...

If you do get some on you don't panic. Just rinse off and you'll be fine...
Click to expand...

I too pre-dilute my acid into a mostly full bucket. It might not be best for beginners since it is another handling step, but I am used to handling chemicals on a regular basis.

TO the OP, just use care, and add acid very, very slowly, and you'll have no worries.
 
If you have tools in your garage I WOULD NOT store MA in the garage. I had a jug of MA in the garage at our old house, before I had a pool. I used it in my cleaning business for cleaning severely neglected bathrooms. I don't know how or why but it exploded, now all of my husbands tools are corroded and he is MAD.
 
I hate handling MA, but I like what it does for my pool. To make it easier to handle I did the following. Got a half high roughneck tote and drank 14 bottles of PowerAide. Rinse bottles and put Some Mr Yuk stickers on them and wrote acid on sides and cap with sharpy. I wait for a day with a slight breeze, put on protective equipment and transfer MA from gallon jugs into PowerAid bottles. 32oz of MA lowers PH in my 25k pool by .2. Rinse bottle and cap in pool and put in tote. When 2 bottles left, I buy 3 more gallons of MA and refill. Yes, an extra step...but it works for me.


Sent from my iPhone using Tapatalk
 
"Failed Chemistry" asked a question that's on my mind about shelf life of MA. My gallon bottle of Transchem muriatic acid says to dispose of it after 6 months. Mine is about a year old. I didn't think it expired, but now that I've read the label... I have added 6 oz to my 6000 gal pool twice in 4 days and after a day or two the pH is at 8, either still or again, not sure because I didn't test it for a day or so. Never had to add the acid more than occasionally during a season before, so I'm wondering if it has used up its potency to do the job, or, as I saw in other threads, sometimes that's just the way it is. Also, might the age of the acid (and deterioration of the plastic jug) be the cause of the basement "explosion" someone wrote about? At any rate, I will take what's left of mine to the toxic waste drop off and get a new bottle. Thanks for any comments.
 

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