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

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

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
His is post #3

An article he authored is Chemistry And The Aquarium: Solutions To pH

And some more reading about the whole subject is available High pH: Causes and Cures

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
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 ...

(((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
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 ...

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.