Muriatic acid?

[Rick.45cal]

Cool tool! I am gonna keep this one for when I need it.

 

[Randy Holmes-Farley Verified Community Expert]

A little update. Friday night I mixed up 15 gallons of salt water and added 8 mL of Muriatic acid. This dropped the dkh from 10.4 to 8.3. Saturday morning I did a water change with no side effects at all. If I would've done this without adding the acid my SPS coral would have shown signs of burnt tips from the alk swing.

Glad that worked for you.

Did you check the pH in the new water?

 

[smh254]

Glad that worked for you.

Did you check the pH in the new water?

I did not check the pH in the freshly mixed saltwater. I aerated the water overnight while it was mixing. It dropped the PH in my tank about .03 apex probe. I do dose 4ml of BRS alk 8 times day so depending on when that went off that could've affected the pH a little. Worked perfect for me. Thanks!

 

[GainesvilleReef]

I do this all the time if I am doing a water change above 15%. I have always followed Randy's method. I usually aerate over night to blow off the co2.

 

[jason2459]

My point was not to get hung up on commercial terms like Muriatic acid (Bleach is another). Its just an over-the-counter HCL/water solution (not lab grade). Like I said previously, it's the last thing I would do, however if smh254 has a need, and follows Randy's procedure, then I'm sure its ok.

Does that make sense?

Calling it Muriatic acid is a fairly generic and common term for it(aka an aka). Plus if someone wants to pick it up locally it's easier to tell them to look for Muriatic Acid as it will be right on the front of the label.

FYI, bleach is also a common name (though could be not as clear as Muriatic acid for ingrediants). Not a commercial name. That would be something like Clorox which could include many other things in the cleaning solution then just bleach (sodium hypochlorite).

 

[TX_Punisher]

Is it safe to dose muratic directly to the tAnk a drop or two at a time? (1/2 ml or so over the course of a day to the sump area).

I'm having a b of a time getting my alk down even with low alk mix water changes.

 

[landlubber]

Is it safe to dose muratic directly to the tAnk a drop or two at a time? (1/2 ml or so over the course of a day to the sump area).

I'm having a b of a time getting my alk down even with low alk mix water changes.

I wouldn't. if you make an error in pails of salt its an inconvenience... if you make that same error in your display you could easily crash the tank. from what I've been reading it also brings your ph down fairly aggressively so you would likely mix saltwater overnight with a airstone or pump and allow that ph to rise again.

 

[Velcro]

The equation I use:

If I make ten gallons of fresh saltwater and want to drop the dKH from 9 to 7--> 10 * 2 * 0.123 = 2.46mL

10 is the volume of water
2 is the desired change in dKH (9-7=2)
0.123 is a constant

I prefer to put some of the muriatic acid in a 4 oz. glass amber bottle with a glass pipette. I then measure out the amount on a cheap jewelers scale in a shot class. I just treat it as 1gm = 1mL on the scale (I think this is only about a 10% error, but feel free to do a specific gravity calculation to get the exact weight to use).

I like weighing it because i can keep my face way away from the measuring process. This is instead of trying to use a graduated cylinder or something where I have to hold it at eye level. Just my preference.

You can find the glass bottles on amazon. Make sure you label it as poison and keep it away from any potential children/pets. Preferable measure it outside... I'm fortunate to have a ventilation hood near my water mixing station, where I brew beer

 

[reefndude]

I've been using muriatic acid for a few years now. I use a syringe and fill 7.5 ml and add to 20g salt water. Instant ocean. Let it aerate for a day or two. Alk reads 7.8

 

[Velcro]

Oh and don't forget to aerate the water really well at least overnight before using. pH will drop and you need to scrub of the CO2 created from the HCl addition.

 

[Randy Holmes-Farley Verified Community Expert]

Oh and don't forget to aerate the water really well at least overnight before using. pH will drop and you need to scrub of the CO2 created from the HCl addition.

That's a prime reason to not do it in a display tank unless it is an emergency, or if you do, do it very slowly spread out over days.

 

[gbroadbridge]

I found this old thread which provides some answers for a problem I have, but I cannot work out where the number of 11,000 mEq/l for HCl comes from.

I guess I'm stuck going from the MW of HCl of 36.46 g/mol, or am I looking in the wrong direction.

 

[GARRIGA]

If it’s good enough for one the all time great discus breeders then why not have at it.

 

[Randy Holmes-Farley Verified Community Expert]

I found this old thread which provides some answers for a problem I have, but I cannot work out where the number of 11,000 mEq/l for HCl comes from.

I guess I'm stuck going from the MW of HCl of 36.46 g/mol, or am I looking in the wrong direction.

I calculated it.

If you are concerned about it, you can look it up:

Hydrochloric acid - Wikipedia

en.wikipedia.org

From the table:

34% HCl is 10.7 moles/L, or 10,7000 meq/L

Other concentrations of muriatic acid can also be taken from that table.

 

[mogood]

I'm curious as to why you say don't do it. I did it for the first time a week ago and it worked perfectly.

how much muriatic acid did you use to lower alkalinity

 

[Mperry622]

I never lower mine by more than 1 point in 24 hours. I follow the rule I found on this forum and maybe even in a mentioned post in this post. 1.2ml muratic per 10G of water. I just dropped my display down a point. 66ml mixed into a gal of fresh water. I skipped the ATO schedule this morning. Added it slowly to the sump. never had an issue. I always lower alk in mixed salt for a few days with an air stone. but I swear my all4reef dose has been doing weird stuff to alk. I used to mix it up in 5 gallons and drip it into the sump but my dripper turned into a facet once and didn't see any ill effects.

 

[GarrettT]

how much muriatic acid did you use to lower alkalinity

Mine fluctuates from 2.5-5ml per 25 gallons. This brings my IO regular salt down to about 8 dKH. I modified a return pump to help drive the ph up. I have another female union with a vinyl hose attached to help with the WCs. This way I can use the same pump for mixing and the WC.

 

[GlassMunky]

Here's a cut and paste for standard muriatic acid. Yours is more dilute (to get less fumes and cost less):

You can use muriatic acid or certain freshwater buffers to lower alk.
Both will lower pH similarly and a lot. There's no way around the pH lowering when reducing alkalinity. You do not want to add CO2. You want to remove CO2 from the tank via aeration.

For that reason, it is best to do it in water change water that is aerated to raise pH before using, or to do it very slowly in the tank (over many days).

The "acidity" (that being essentially negative alkalinity) of 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).

I would not drop more than 1 dKH per day due to the big pH drop in a reef tank, but in new salt water it is fine.

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

You can also use Seachem Acid Buffer:

http://www.seachem.com/Products/product_pages/AcidBuffer.html

how long after adding the acid to new saltwater do you need to wait before testing again for ALK? (to make sure it dropped the correct amount)

 

[Miami Reef]

how long after adding the acid to new saltwater do you need to wait before testing again for ALK? (to make sure it dropped the correct amount)

The reaction is instantaneous. You can test immediately. It’s a good idea to stir the water for a few minutes to have it homogenous.

 

[Randy Holmes-Farley Verified Community Expert]

You will also want to wait to blow off the excess CO2 before using it.