A vingar reactor

[saveafish]

Now, since I have seen a lot of nitare reactors and dosing vingar. Whay not combine both. Using vingar and calcium media. This would add calcium while dosing vingar at the same time. Would this concept even be worth trying?

In theory the vingar would desolve the calc, reduce the nitrates and dose both into the tank.

Any thoughts on this theory.

 

[Randy Holmes-Farley]

Here's a copy and paste of my answer from the other thread:

You could try to do that, but one problem is that you wouldn't be able to control vinegar and calcium/alkalinity additions separately.

It also won't supply much since the vinegar doses are not that high in relation to alkalinity needs in many tanks. It will be less than simply adding lime into vinegar directly and dosing the saturated solution, which is what I did for a while.

I dose 100 mL of vinegar into my reef tank. If all of that dissolved calcium carbonate, you might get at most 166 milliequivalents of alkalinity. In my water volume that would add about 0.5 dKH per day. The limewater I add for top off brings in a few times that.

 

[Mike_Noren]

There's no one I trust more than Randy on aquatic chemistry, but 100 ml of 12% acetic acid is 0.2 mole, theoretically capable of dissolving 0.1 mole of calcium carbonate, equal to 10 grams of calcium carbonate (someone correct me if I'm wrong, I've got a killer headache and it's fifteen years since I read stoichiometry). That'd be a half-an-inch cube of solid limestone - doesn't seem a trivial amount to me?

EDIT: ...and 10 grams of calcium carbonate is just 200 meq. Remind me to just take your word for it next time.

 

[Randy Holmes-Farley]

Here's the full math...

100 mL of vinegar (5% acidity) = 5 grams of acetic acid.

MW of acetic acid is 60 grams per mole, so that 5 grams is 0.083 mmoles.

If we assume twice what you did to give it the benefit of the doubt that one mole acetic acid dissolves one mole of CaCO3 (making HCO3- and not CO2/H2CO3 in the process), then you are adding 2 x 0.083 = 166 millimoles of alkalinity.

166 milllimoles added to 100 gallons is 166 mmillimmoles/100 gallons x 3.79 L/gallon = 0.44 meq/L or 1.32 dKH per day.

My system volume is about 250 gallons, so in my tank that corresponds to about 0.5 dKH per day, and as I mentioned, I already add several times that in alkalinity via limewater, and my tank is not by any means a high alk demand system since I have no SPS.

 

[Mike_Noren]

Always interesting to see these cultural differences - pickling lime is nonexistant here, it's simply not used, and our vinegar is 12%...

 

[Randy Holmes-Farley]

Yuck. Must make for pretty strong salad dressing.

 

[Mike_Noren]

Yuck. Must make for pretty strong salad dressing.

Oh we have the weaksauce kind too, balsamico, apple cider vinegar and white/red wine vinegar, but spirit vinegar made from ethanol is the stuff used by real men (for things like pickling herring)!