Dark Muriatic Acid

[tiride]

I've been pouring muriatic acid into my pool for over 10 years. I opened a bottle today and it looked like dark urine. I looked it up and it sounds like it might have been contaminated with iron. I know iron in pool water can promote staining. I'm concerned about using this bottle of acid. Is it safe to use or should I discard it?

 

[JoyfulNoise]

It’s likely a very low level of iron. Ferric chloride (which is what imparts the yellow color) is a very dark brown/yellow substance when pure. So it takes only a minute quantity of it to turn a gallon of water yellow (a few ppm at most will yellow water pretty good). But then you’re pouring ounces of it into tens of thousands of gallons of water. It’s not a big deal. But, if it bothers you, then maybe you can return it from where you purchased it?

 

[98Poolmaster]

I've been pouring muriatic acid into my pool for over 10 years. I opened a bottle today and it looked like dark urine. I looked it up and it sounds like it might have been contaminated with iron. I know iron in pool water can promote staining. I'm concerned about using this bottle of acid. Is it safe to use or should I discard it?

It shouldn’t do anything like Joyful Noise said it’s only a few ppm to cause the colour to change.I would recommend Acid Blue if you can locate it in your area we sell it and has no fumes and safer if drops fall on concrete or wooden decks.

 

[tiride]

Thank you both!

 

[kul]

Acid Blue

Typically anything labeled with “blue” is code word for copper so you may want to confirm that there aren’t any additives that could be mistakenly put into your pool water.

 

[98Poolmaster]

Typically anything labeled with “blue” is code word for copper so you may want to confirm that there aren’t any additives that could be mistakenly put into your pool water.

It has been confirmed from the manufacturer it is 31% MA .I don’t see why they would put copper in MA that makes little sense.

 

[reggiehammond]

What other magical substances are added to it to reduce fumes? I wouldn't put that into my pool without understanding what it is...

 

[98Poolmaster]

What other magical substances are added to it to reduce fumes? I wouldn't put that into my pool without understanding what it is...

It’s the same as Acid Blue and works exactly the same as MA without the fumes it’s been around for twenty plus years I don’t know what magic you mean?

 

[Lake Placid]

It has been confirmed from the manufacturer it is 31% MA .I don’t see why they would put copper in MA that makes little sense.

The issue I have with these types of products is you cannot confirm the actual strength of the acid. The SDS lists Hydrochloric acid as a percentage of weight somewhere between 10% and 30%. If it was full strength hydrochloric the SDS should state 30% to 40%. So how much of it to add to reduce the ph in a given volume of water is a guessing game of trial and error until you achieve the correct dose. The SDS also states 2 proprietary PH balancers contained in the mix. Why? Not sure, it’s proprietary. Lastly, which likely isn’t a concern for most pool owners, is the additional cost. $4/gallon increased cost isn’t much to consider unless you’re in business using the stuff daily. The product may work just fine, I just don’t like the amount of guessing that has to be used to dose with it in addition to the other downsides.

 

[98Poolmaster]

The issue I have with these types of products is you cannot confirm the actual strength of the acid. The SDS lists Hydrochloric acid as a percentage of weight somewhere between 10% and 30%. If it was full strength hydrochloric the SDS should state 30% to 40%. So how much of it to add to reduce the ph in a given volume of water is a guessing game of trial and error until you achieve the correct dose. The SDS also states 2 proprietary PH balancers contained in the mix. Why? Not sure, it’s proprietary. Lastly, which likely isn’t a concern for most pool owners, is the additional cost. $4/gallon increased cost isn’t much to consider unless you’re in business using the stuff daily. The product may work just fine, I just don’t like the amount of guessing that has to be used to dose with it in addition to the other downsides.

When we first starting using we did field tests and it worked exactly the same as MA.You make valid points,and do any of us really know what these chemical companies put in their products?Unless you have super expensive equipment to measure the actual percentages of what they claim to have.All we can go by is what they say not too many people go the hassle of reading MSDS sheets except people like me or yourself or the experts on this forum.People really like the no fume and buffered aspect of the product,to me it’s no big deal about the fumes and just be careful not to spill it on concrete or wood.It has been spilled on the back room floor and it didn’t stain it.We use MA on pools and the Acid Blue on hot tubs with high TA from well water, our showroom hot tubs are filled with well water and I take care of the chemicals and balancing daily.

 

[Newdude]

It’s the same as Acid Blue and works exactly the same as MA without the fumes it’s been around for twenty plus years I don’t know what magic you mean?

He means the magic labeled right on the bottle.

Lifted from pool school:

Acid Magic​

Acid Magic is basically muriatic acid (unknown strength) that is buffered using proprietary phosphate containing buffers that can, but don't necessarily, breakdown into phosphates. It may also contain a cationic surfactant in it that suppresses fumes.[5]

Acid Magic claims to have:

• 90% Less fumes
• Little to no corrosion caused by fumes
• Can't burn intact skin

A heater can cause the clarifiers and phosphate buffers to breakdown and form calcium phosphate scale. Phosphate scale is incredibly hard to remove as it does not dissolve except in the strongest of mineral acids. Your heat exchanger can get coated on the inside with scale build up that randomly breaks loose. Eventually you can clog the heat exchanger.[6]

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Personally, I don't like additives when it's possible to avoid them. I watch shoppers load their shopping carts with Chlorox at BJs every week when it's warm out, surely some or even most of them don't have foaming issues. But nobody knows the threshold at which they will have issues, so it's a weekly gamble. Even if it's a small gamble, it's a gamble.

I also believe if something is full strength it is labeled as such, probably loud and clear that you'll need less of Manufacturer Xs product. There is no reason to list 10% to 30% on the MSDS unless they are hiding its watered down IMO. They know exactly what strength it is (within reason).

Here are TFP, regional issues also come into play on whether chemicals will build to the point of having issues. IIRC, there is a corner of Louisiana that gets 70 inches of rain a year. Even with mixing, their water is constantly being overfill and diluted so they have alot of leeway. Folks in the southwest need to think of every last thing they add as it won't come out until they drain the pool because the CH got too high. The rest of us with 2 to 4 ft of annual rain fall somewhere in the middle.