Reef Chemistry Question of the Day #14

[Randy Holmes-Farley]

Reef Chemistry Question of the Day #14

Suppose you are an aquarist who wants to use a salt mix with an alkalinity of 7 dKH. You have a free batch of salt mix with an alkalinity of 11 dKH, and you've heard that adding acid to it can be used to drop the alkalinity.

Which of the following, when added to the salt mix, will NOT drop the alkalinity?

1. Hydrochloric acid (HCl)
2. Carbonic acid (H2CO3)
3. Sulfuric Acid (H2SO4)
4. Nitric Acid (HNO3)
5. Hydrobromic acid (HBr)

Good luck!

 

[cheezybuda]

Carbonic acid. It will go into equilibrium with atmospheric CO2 and not affect bicarbonate

 

[beaslbob]

gee I was gonna say nitric acid.

But I don't have any idea on this at all.

 

[Outlaw]

Carbonic would be my guess. Might stabilize pH but I don't think it will help with alk.

 

[Velodog2]

Cabonic acid should act like vinegar, initially dropping alk as the acid is neutralized but then giving it back with the remaining carbonate molecule.

 

[DRThompson]

2.

there is a correction mechanism with the carbonic acid, ph should lower but alk should not. Similar to recipe 2 for 2part dosing.

 

[aznreefer]

Carbonic acid because the others listed are strong acid and wouldn't not dissociate well.

 

[alexp]

Carbon Dioxide or Carbonic acid (H2CO3)which is a weak acid.

Muriatic acid.1(HCL) drops alkalinity.
3. Sulfuric Acid (H2SO4) too.
I am no Chemist but those 2 I know they drop dKH in a reef tank.

 

[CastAway]

Uhhhh.....

...what you need in this case is lysergic acid diethylamide, pretty sure. No, I'm not a chemist.

 

[Mike&Terry]

1. Hydrochloric acid. We've used the diluted form (muriatic acid) to lower alkalinity in fresh saltwater when we had issues with particular salt batches.

 

[aznreefer]

I think the deionization of carbonic acid would release carbon dioxide which would not lower the alkalinity level.

 

[Randy Holmes-Farley]

1. Hydrochloric acid. We've used the diluted form (muriatic acid) to lower alkalinity in fresh saltwater when we had issues with particular salt batches.

The question was...

"Which of the following, when added to the salt mix, will NOT drop the alkalinity?"

 

[Mike&Terry]

The question was...

"Which of the following, when added to the salt mix, will NOT drop the alkalinity?"

LMBO - that's what I get for multi-tasking, errr... or trying to. :redface:

Answer is 2.

 

[DRThompson]

LOL....too much lysergic acid diethylamide

 

[lionfish5740]

I know it's not HCl because I've used it to lower Alk and assume HBr would do the same. Beyond that I'm not sure.

Out of curiosity Randy, I've always heard to test your Alk around the same time of day for consistency. I know that the stony corals use it up and all but is it the CO2 concentration that might cause it to fluctuate on a test kit? Or do I have it mixed up with something else?

 

[leptang]

I would say #2 carbonic acid
Carbonic acid is the end result of AT the strongest H+

 

[leptang]

I would say #2 carbonic acid
Carbonic acid is the end result of AT the strongest H+

TA*** **** dyslexia

 

[leptang]

And only dosed to the correct amout

 

[leptang]

It will increase Ca2+ and CO32-

 

[leptang]

Oh by what i mean of "strongest H+" is the abundance of Hydrogen and the affects it has in seawater on giving to other elements.