muric acid

[brian_tr]

I have very high alkalinity and for the last few years I have used muric acid to bring it down.  I do it in one dose.  I got tired of fighting it over several weeks.  After a fews days it is right on the money.  I have not seen any problems yet from using muric acid but the dealer says this is very bad for the tub so I decided to try the ph down again.    It has been one week and I have added 1lb of ph down and the alkalinity is still above 300.  Is the acid really that bad for the tub?

[Chad]

I have very high alkalinity and for the last few years I have used muric acid to bring it down.  I do it in one dose.  I got tired of fighting it over several weeks.  After a fews days it is right on the money.  I have not seen any problems yet from using muric acid but the dealer says this is very bad for the tub so I decided to try the ph down again.    It has been one week and I have added 1lb of ph down and the alkalinity is still above 300.  Is the acid really that bad for the tub?

Muriatic acid is fine, especially when one's alkalinity is as high as yours out the tap. Like you've seen, it's almost impossible to bring it down with sodium bisulfate when it's that high. I think your dealer just likes all the money he makes on pH down.

[tony]

The problem with muriatic acid is handling.  If you spilled some on your spa and sustained some kind of damage you wouldn't get any warranty relief.  Once its in the water its no problem as Chad stated and in many situations works better than dry acid.

[Honorable]

I have very high alkalinity and for the last few years I have used muric acid to bring it down.  I do it in one dose.  I got tired of fighting it over several weeks.  After a fews days it is right on the money.  I have not seen any problems yet from using muric acid but the dealer says this is very bad for the tub so I decided to try the ph down again.    It has been one week and I have added 1lb of ph down and the alkalinity is still above 300.  Is the acid really that bad for the tub?

Muriatic Acid is fine to use with the tub, as stated above.  You are just trying to make a chamber of zero Alkalinity to "burn off" some of the access.  The doseage can be tricky, when putting in too much at once can cause problems with the tub.  Too high of a dose, could cause problems with the shell, jets and such.  Dripping like stated above could void warrantees, so use extreme caution when using Muriatic.

I don't usually recommend Muriatic, as most of my customers have children.  Since Muriatic Acid is relatively clear, children may mistake it for something harmless and have an accident.  So, if you are clear on the dosage, careful with the product, and store it in a cool safe place, there shouldn't be an issue.

Do you have a high metal content with that high alkalinity?  Copper, Iron, etc?  How about Hardness, is that high as well?

[C-MeToasty]

Oh and most importantly don't mix muriatic Acid with Sodium Hypochlorite or any other oxidzer otherwise you will have a Nice Mustard gas like they used for WW1.  

[TubsAndCues]

Oh and most importantly don't mix muriatic Acid with Sodium Hypochlorite or any other oxidzer otherwise you will have a Nice Mustard gas like they used for WW1.  

Isn't it any kind of hypochlorite?

But for another safety tip, if you are ever diluting or pre-dissolving chems, make sure you add the chems to water, never the other way around.

I've seen what can happen if chems are mixed together or improperly.  Chemical burns are nothing any of us would want to endure.

[C-MeToasty]

Oh c'mon sport.  You are not a true hot tubber than. hehe

[sonofsail]

Muriatic acid is an industrial grade hydrochloric acid.  It is fairly dense straight out of the bottle.  The worry is when adding it straight to the tub, it will go to the bottom and be circulated before it has a chance to be fully diluted.  This can cause corrosion to any metal in the pump/heater.  Best way to use it would be to dilute it by adding it to a bucket of water (in that order) before adding it to the tub.  Definitely do not get the straight stuff on anything and do not mix it with any other chemicals.   It would also be a good idea to store it outside away from anything metal that you don't want to corrode.

[Brewman]

I've been using muriatic acid for years on my spa, and I'm still alive.  It's all in learning to handle the stuff.   And my spa hasn't been harmed in the least.

I take a clean pail, and scoop out about a gallon or two of spa water.  Then I add the muriatic, swirl the pail carefully to mix, then slowly pour this mix back into the spa.

I have VERY high alkalinity tap water and this stuff is extremely cheap when compared to the normal Ph decreasers sold for spa use.  

This stuff is sold off the shelf in the paint department of all the big boxes- for about $2 per gallon.  Just be careful and you'll be fine.  For sure don't dump it straight from the bottle into the spa.  

[brianu]

I too have extremely high alkalinity and PH in my tap water, and have also discovered that the dry alkalinity/PH decreaser doesn't work very well in lowering alkalinity and PH in my case.

My questions are as follows:

1.  Will muriatic acid also lower PH?  If not, any suggestions on alternatives to the typical spa decreaser to lower PH?

2.  Is there are general recommended ratio of muriatic acid-to-water to treat a hot tub when trying to lower alkalinity?

[Lars]

I have very high alkalinity and for the last few years I have used muric acid to bring it down.  I do it in one dose.  I got tired of fighting it over several weeks.  After a fews days it is right on the money.  I have not seen any problems yet from using muric acid but the dealer says this is very bad for the tub so I decided to try the ph down again.    It has been one week and I have added 1lb of ph down and the alkalinity is still above 300.  Is the acid really that bad for the tub?

It is if you put it all in at once.

Should do it in small doses, about 1/3 cup, till you get close to the ALK number you want, then switch to PH Down, just for fine tuning and easier handling of the even smaller remaining doses needed.

[Brewman]

Muriatic acid is pretty strong right out of the bottle- keep your nose away.

My usual process is to scoop out a few quarts of spa water into a clean container, like an ice cream bucket.  Then add an ounce or so of acid, swirl carefully, then slowly add that mix back into the spa.  Disperse this over a wide area, and have a pump running so it all gets mixed well.

Check your ph or alk later, and repeat.  As you do this, you'll get a feel for how much acid to use for a certain drop.  

Just be careful with the muriatic.  Don't add directly to the spa- it's that kind of thing which might cause harm.  

[BauerN]

Muriatic acid is an industrial grade hydrochloric acid.

It's actually diluted a bit (relative to other forms), primarily used for cleaning concrete and corrosion.

Posts referring to safety as the only disadvantage over bisulfate are right on.  Muriatic acid is stronger, quicker, and cheaper.

1.  Will muriatic acid also lower PH?  If not, any suggestions on alternatives to the typical spa decreaser to lower PH?

Yes, it is very effective.

[tony]

The Taylor water chemistry booklet gives the amount of muriatic acid to use to lower pH using its acid demand test...0.37 fluid oz at 31.45% per drop acid demand reagent in 400 gallon spa.... and alkalinity...1.02 fluid oz at 31.45% to lower alk 10 ppm in 400 gallon spa.

[brianu]

A HUGE thanks to all for the great and speedy input!  

Just for the good-of-the-order, a buddy of mine pointed me to a product called Acid Magic (Certol International, LLC).  It's purportedly as effective as muriatic acid without the handling hazards.  I found some info on it here:  http://www.certol.com/AcidMagicHome.ASPX.  I may give it a try next time around.

Thanks again!