Muriatic Acid

[paphater]

I set up a new tank and I need to bring the alkalinity down. I picked up a bottle of this but I wanted to make sure it was ok before I went ahead and used it.

https://www.lowes.com/pd/Crown-1-Gallon-Muriatic-Acid/4146121

 

[Randy Holmes-Farley Verified Community Expert]

Why do you think you need to bring the alk down fast instead of just allowing it to drift down?

Yes, that is a suitable product, but it is more dilute than full strength muriatic acid so needs a bit more. They promote the lower concentration as a benefit for you (low fumes), which may be true, but it also costs them less.

 

[paphater]

I'm transitioning everything over to a new tank that I used IO salt on. I'd like to try and match the alkilinity between the two. I haven't actually measured the dkh on the IO yet but I assume its more than the 9 dkh that I shoot for. Once I do measure it, any tips on a starting point point to lower it since I got the weaker version?

 

[Randy Holmes-Farley Verified Community Expert]

Normal muriatic acid is about 35% HCl. Check the label and see what it is. Likely something in the 20's (say, 28). then adjust upward by the ratio 36/28 = 1.29.

For normal muriatic acid,

Be very careful with straight muriatic acid. It can easily burn you, especially your eyes.

The "acidity" (that being essentially negative alkalinity) of full strength muriatic acid straight from the bottle is about 11,000 meq/L.

So adding 1/11,000 of the water volume as this acid will drop alkalinity by 1 meq/l (2.8 dKH).

That sounds like a good dose.

You'll need to aerate well after adding the acid to blow off the excess CO2 and bring up the pH.

 

[Shon]

Be very careful with straight muriatic acid. It can easily burn you, especially your eyes.

+1 , Fumes are harsh too. Cough, cough.

 

[paphater]

Normal muriatic acid is about 35% HCl. Check the label and see what it is. Likely something in the 20's (say, 28). then adjust upward by the ratio 36/28 = 1.29.

For normal muriatic acid,

Be very careful with straight muriatic acid. It can easily burn you, especially your eyes.

The "acidity" (that being essentially negative alkalinity) of full strength muriatic acid straight from the bottle is about 11,000 meq/L.

So adding 1/11,000 of the water volume as this acid will drop alkalinity by 1 meq/l (2.8 dKH).

That sounds like a good dose.

You'll need to aerate well after adding the acid to blow off the excess CO2 and bring up the pH.

Thanks Randy. Oddly enough I couldn't find the strength on the bottle but the website says "Strength 10° baume (15.725%)." No wonder it has bad reviews saying its too weak. At that strength, what do you think? It's for about 180 gallons of water volume.

 

[Randy Holmes-Farley Verified Community Expert]

Double the recipe I gave.

 

[paphater]

Thanks!

 

[cwk84]

How long would the mix need to be aerated to get the pH up? I changed from Red Sea Pro to Reef Crystals and the dkH is off the charts at 35ppt. I want to bring it down some.

 

[Randy Holmes-Farley Verified Community Expert]

Depends on how effective your aeration and the CO2 level in your air.

 

[cwk84]

By how much does it lower the ph?

 

[Randy Holmes-Farley Verified Community Expert]

A lot, but I haven’t measured it and it depends on how much you drop the alk. It likely cannot be used without aeration, but a few days is likely plenty.