Can Muriatic acid be left outside?

dubele

Well-known member
Jun 17, 2013
150
Southeast Pennsylvania
Hi,
I keep my pool supplies inside and was wondering about Muriatic acid. I was wanting to start keeping that outside by my pool equipment. It is in a plastic bottle. It would be exposed to the outside elements including quite a bit of sun. Will this degrade the acid?
Thanks,
Doug
 

mknauss

Mod Squad
TFP Expert
Bronze Supporter
May 3, 2014
33,316
Laughlin, NV
You should keep the MA bottle in another plastic container to protect it from the UV impact on the bottle. I use a 20 gallon plastic trash can with lid. Others use a 5 gallon bucket with lid. Do not store too close to your pool equipment. The fumes will corrode metals quickly.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,930
San Dimas, CA (LA County)
The acid will easily outlast the plastic jug if left to the elements, especially to the sun. Outdoors is great, but shade it. Or keep it in a plastic bucket with a lid which also serves as a secondary containment vessel
 

crackers8199

Well-known member
Jun 5, 2014
121
Lake Elsinore, CA
You should keep the MA bottle in another plastic container to protect it from the UV impact on the bottle. I use a 20 gallon plastic trash can with lid.
this is exactly how i store mine. i keep it on the side of the house that gets less sun, not sure if that really matters but it makes me feel better about things...
 

HeyEng

Gold Supporter
Silver Supporter
Nov 7, 2018
567
Oklahoma City, OK
I would not keep it air tight. Mine is pretty loose so it ventilates.
Just curious as to your reasoning for the ventilation. I buy mine at the local HD and it sits outside (in the sun!) for pretty lengthy times. I keep mine in a shed (nothing but the MA and some other junk) and I don't seem to have had any issues. Also, if you have say...5 gallons...do you open the lid, remove the plastic "seal" and then put the cap on loosely?
 

revitup

Gold Supporter
Bronze Supporter
Nov 30, 2019
351
Pawleys Island, SC
Do the bottles seal tightly or not? I thought I read on this site that they were vented? I thought the vented fumes would corrode metal in the immediate area if kept in an enclosed garage or shed?
 

zea3

Mod Squad
TFP Expert
LifeTime Supporter
Jul 10, 2009
12,670
Houston, Texas
MA is usually sold in bottles with vented caps. It will outgas, which is why it shouldn't be stored near anything made of metal.
 

Newdude

Well-known member
Jun 16, 2019
4,568
NY
I kept a gallon in my garage on a shelf full of various other liquids for years just a few feet from all my tools, screws and miscellaneous items. I didn't know better before here, but I also never saw any ill effects. Maybe I was lucky or my brand didn't use a vent cap. I dunno.
 

revitup

Gold Supporter
Bronze Supporter
Nov 30, 2019
351
Pawleys Island, SC
MA is usually sold in bottles with vented caps. It will outgas, which is why it shouldn't be stored near anything made of metal.
Don't mean to beleaguer this but I'm still confused. I see above where some feel the cap needs to be left loose to vent implying that it will not vent if tight. Another post says the bottle has a 'plastic seal'. How does it vent when it's sealed? Do the storage precautions only apply to opened bottles?
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
23,930
San Dimas, CA (LA County)
Don't mean to beleaguer this but I'm still confused. I see above where some feel the cap needs to be left loose to vent implying that it will not vent if tight. Another post says the bottle has a 'plastic seal'. How does it vent when it's sealed? Do the storage precautions only apply to opened bottles?
The answer is both.

I imagine the ones sold 2/case and shipped in cardboard boxes are shipped sealed. It's been so many years since I bought it that way I forget. I get mine 4 to a plastic crate in refillable bottles and they're not sealed. And once any of them has been opened, they're vented. Marty lives next door to Hades, so he has to worry about heat expansion more than normal people do.
 
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