Formula for lowering Alk using Muriatic Acid

[gregzz4]

Muriatic Acid is an impure form of Hydrochloric Acid. I'd recommend against using it on a regular basis to adjust your Alk levels, but sometimes you get those bad buckets of salt, so ... let's use some

If you want to skip all the links, disclaimers etc, skip to the bottom for the guts of the post.
But you've been warned about the uses of this stuff :microwav:

DO NOT ADD ANY MURIATIC ACID DIRECTLY TO A SYSTEM CONTAINING LIFE
Also, do not add any MA to water you're about to use without first checking the pH after.
The effect of a significant drop in pH will most suredly kill most or all life in short order !!!
It can take many hours for the pH of water dosed with MA to come back up to acceptable levels, so use it with some smarts.

Using it comes with some responsibilities;
10 Muriatic Acid Safety Tips (http://www.doityourself.com/stry/10-muriatic-acid-safety-tips)

Muriatic acid is readily available to most of us, but has impurities in it that Hydrochloric doesn't. Too bad for most of us. I'd rather use the purer form.

Regardless, I took some time to decipher a post by Randy Holmes-Farley to come to my final numbers.
You are welcome to check my math by visiting the post I based it on here (http://www.reefcentral.com/forums/showthread.php?t=1530419)
His is post #3

An article he authored is Chemistry And The Aquarium: Solutions To pH (http://www.advancedaquarist.com/2002/6/chemistry)

And some more reading about the whole subject is available High pH: Causes and Cures (http://reefkeeping.com/issues/2005-03/rhf/#7)

I completely agree with his thoughts on the long-term use of such a drastic measure, but when it applies to a bad bucket of salt used for water changes and such, I feel we can safely use the acid to adjust the Alk level in said water to match, or come close to, the water we are adding it to.
Just be sure it's well aerated after the addition of acid, and before adding the water to any system containing life :smile:
Another consideration is the amount of Calcium Chloride that will become available after the Alk is dropped. This is something I haven't tested yet, but will do so in the next week as I'm due for a WC.

And one more thing;
Lets make sure that you don't take anything I'm writing now as gospel. I've been known to make mathematical mistakes before, and haven't had time to test this formula in the real world !!!!!
As I stated above, I'll test it next week when I perform my next WC and report my findings.

So, lets get on with it.
From what I can calculate, based on what Randy states, it only takes 0.12287 ml of muriatic acid, or 0.123ml, or basically less than you can measure, to drop 1 gallon of saltwater by 1dKH ...
Absorb that for a second ...

To use 1ml of Muriatic Acid to safely drop the alk in any volume of saltwater, as near as I can calculate, it will drop the dKH of 8 gallons <> by 1 point.
So, lets be careful kids, this stuff is potent.

Here's my formula; I'm kinda proud of it, so don't bash me unless you find a significant error. After all, I did figure it out and post it when no one else has yet ... :wink:

(((A)*3.785)/(11000/((B-C)/2.8)))*1000

That's it. Pretty simple, huh ?

I'd recommend, because of the complexity of the formula, that you copy/paste it into a Google search.
Then change the letters to reflect your numbers and hit enter.
And be VERY careful not to change any of the other parameters while doing so !!!! Even the loss of a ( or a - will throw the formula into space !!!

I will not be held responsible for whatever amount you dose of MA to your water, but you're more than welcome to PM me if you are concerned about the final # you've come up with. I'll gladly check it against my block-head and let you know if it's correct or not.

OK, I'll elaborate :mrgreen:
A is the amount of water you need to affect. IE your new Saltwater.
B is the Alk reading you achieved from your test kit of your new Saltwater.
C is the Alk reading you achieved from your test kit of the water you will be adding this newly mixed saltwater to, or the Alk reading you want to match.

Be very careful when entering the numbers into the formula !!!!
I hope I'm making this clear enough as dosing Muriatic Acid is very, very something ... :surprise:

Again, it only takes 1ml of MA to drop 8+ GALLONS of water by 1dKH

Play safe kids, and have fun.
Oh, don't forget to check your Ca levels after the pH has come back up as it's likely your Calcium Chloride levels have risen, but I think I mentioned that above.

[gregzz4]

Um, I feel the need to add the fact that the # you achieve from the formula is in ml, IE millilitres. That's why I divided a litre by 1000 at the end :mrgreen:
Just sayin' ...
Don't be takin' the # you acheive from the formula and think that when it gives you a number of, say, 12.14, it's telling you to add 12 litres of acid :twised:
It really means 12.14ml
That's less than a tablespoon dammit, so watch your dosing :silly:

[Myka]

Great post! I didn't check your formula, but your numbers sound right. I used to use muriatic acid to lower alk when I was using H2Ocean salt. I did find that Randy's formula didn't work perfect for me - not sure why. His formula lowered the alk more than expected. I ended up with 6 dKH On my first try when I was aiming for 7.5 dKH. :lol:

[gregzz4]

Thanks Mindy!
I'm not much on composition, but at least I can spell (mostly)

I wonder if there are different 'strengths' of MA out there. This could be why your attempt to use Randy's recommendations didn't work out.
I'll be posting my results next Tues/Wed

[gregzz4]

Successful usage results ...

First, I want to emphasize how important it is to be careful when using Muriatic Acid (MA)
This stuff will burn through pretty much anything you spill it on;
Carpet, skin, metal, some plastics, your countertops and hardwood floors, cats and dogs, even gerbils :surprise:
Plus some things it reacts with can become very toxic once airborne and will create some very serious gasses.
Please be super careful with it.

http://powerpoint.sonyanancysims.com/mypictures/GetWell/HF%20Green_sick_face.gif

It will displace the oxygen in your lungs, so, if you happen to be exposed to any serious fumes, don't try to breath but walk away while exhaling, and then take some breaths while you're clear of the fumes.

With that said, I used this, and Pure Hydrochloric, along with Phosphoric, Caustic Soda, and straight Nitric acid for 23 years.
You'd think I'd know better ... Well, I spilled some :doh:

I was being very careful when measuring out what I needed, doing so inside the laundry tub, and sealed the container very well when I was done.
I then carelessly carried the bucket I keep the MA in, along with a vial of 6.5ml acid, and promptly walked into something in the way, spilling the vial as I went.
Thankfully it only spilled on some crappy old carpet, but it still made a big mess. It burned right through the carpet to the backing before I could grab some water to dilute it.
After trying to soak up the worst of it with some old rags, I shook some baking soda over it and then soaked it with water.
Needless to say, there are big holes in the carpet now :mrgreen:

Play safe with this stuff, or it'll bite back


So, I successfully performed my first 'new salt water' acid dosing.
I calibrated my pH probe first, just to be safe
I started with new water at;

Alk 12.1
Ca 370
Mag 1050

Not knowing what would happen to the Ca and Mag after dosing the MA, I decided to bring the Mag up to an acceptable level first. I proceeded to raise it to 1350.
Then I double-checked my Sg and found the Mag had raised it from 1.026 to 1.027. I added some RO to bring it back down, and the Mag dropped to 1290 aarg.
Not going to play that cyclicle game. Back to altering the Alk.

So now I'm dealing with;

Alk 11.5
Ca 360
Mag 1290

The MA I used is from Canuck Tire Ro-Tyme Muriatic Acid (http://www.canadiantire.ca/en/pdp/ro-tyme-muriatic-acid-4-l-0491064p.html)

My formula works !!
I wanted an Alk reading of 7.7, and the formula told me to use 12.84ml of MA, so I started off with 6.5ml
This resulted in;

Alk 9.75, and the pH dropped from 8.1 to 7.1
After waiting 10 or so minutes, I added another 6.5ml of MA
This resulted in;

Alk 7.85
Ca 365
Mag 1290
pH 6.85

I aerated the water over night with an airstone and tonight I tested;

Alk 8.3
Ca 365
Mag 1290
pH 7.82

As you can see, it looks like there is a bit of an adjustment period for the Alk level after using the MA. Overnight it rose from 7.85 to 8.3

IF I ever need to use it again, I'll do the same as this week and let it sit overnight before re-testing the big 3. Then I'll adjust the water as needed at that point.

So, I'm happy to report that using MA to drop Alk is do-able if done safely, and it doesn't appear to adversely affect either Ca or Mag.
I'm actually surprised as I was expecting the Ca to rise as the Alk dropped.

[Myka]

Success! ...besides the carpet! Also keep in mind that muriatic acid will also damage stainless steel - it stains it a dull grey color.

[dino]

I didn't read the whole post as its really lengthy but I use hydrochloric acid everyday at work and we take full precautions when dealing with it. it comes in at 33% but will decrease with age. I have a formula I use if you wanted it

[hfp75]

Success! ...besides the carpet! Also keep in mind that muriatic acid will also damage stainless steel - it stains it a dull grey color.

I agree !!! Found that out the hard way.... My SS basement bar sink has spots now.....

:cry:

[gregzz4]

I have a formula I use if you wanted it
What kind of formula and does it apply to our aquariums?
I wrote a formula that directly applies, and it's in the first post.

For simplicity, here it is again;

(((A)*3.785)/(11000/((B-C)/2.8)))*1000

A is the amount of water in gallons you need to affect. IE your new Saltwater.
B is the Alk reading you achieved from your test kit of your new Saltwater.
C is the Alk reading you achieved from your test kit of the water you will be adding this newly mixed saltwater to, or the Alk reading you want to match.

Something I forgot to mention in the first post is, A is in gallons