View Full Version : Adding vinegar to 2 part's Alk suppliment

10/09/2017, 08:00 AM
I started using 2 part dosing instead of kalk dosing about a month ago and I also dose vinegar as a carbon source, and I got to wondering if there would be any benefit to mixing my daily dose ov vinegar to the alk part of my 2 part prior to dosing the tank, or any negative effects.

I was going to try it last night, and added the vinegar to a dose of the Part B and it fizzed for a bit when I mixed them, then stopped and was a clear water looking liquid. I started to dost that to the tank and didn't get the white cloud I normally get when dosing the alkalinity. I only added a few ML's of the solution and thought i better stop in case there is something wrong with that method.

Any thoughts on this? I don't know if there would be any harm in dosing this way, and don't know if there's any benefit either. Just sort of a weird thought I had. Maybe the alk is better dissolved and would disperse better? maybe I'm breaking it down or using up the vinegar and reducing the effectiveness of the vinegar dosing? I'm just not sure at all.

For now I'll just dose normal, but am curious to see what other's thoughts might be.

10/09/2017, 04:01 PM
Mine the two is fine. The vinegar is lowering the pH of the solution, which is why the cloud didn't form. The cloud is magnesium hydroxide:


10/10/2017, 12:05 PM
Thanks for the link. Makes sense to me after reading what is going on. The way I read it, it wouldn't matter either way if the alk and vinegar were mixed prior to dosing or dosed seperatly. Because there doesn't seem to be an apparent benefit, i think I'll stick with dosing seperatly.

10/10/2017, 03:33 PM
You are correct. Dosing together or separately will have identical results in most situations. In your case, either will be fine. People who are dosing close to the point of precipitation might do a bit better if the two are mixed together, but that's very, very rare.

10/11/2017, 06:55 AM
I don't plan on doing it at this time, but just to be thorough, Would it be safe to store a mixture of vinegar and the alk part after they are mixed? Say I wanted to pre-mix a couple week's worth, and dose the whole solution daily just to have one less thing to dose.

My guess is it would depend on the resulting solution's pH and if it were low/high enough to inhibit bacterial growth.

10/11/2017, 10:37 AM
I prefer to keep the carbon dosing separate for more precise control and simplicity.

10/11/2017, 12:20 PM
I agree that there might be some issue with keeping the solution from decaying, so I would be careful. It might be fine, though. You could try a test solution.

10/11/2017, 10:06 PM
Isn't the loss of CO2 with the addition of acid counter productive to the main goal of putting carbonate in solution. Seems like you are making the all less potent.

10/12/2017, 08:40 AM
The CO2 will effect the pH but the goal for adding carbonate is increasing the alkalinity.

I agree with Jon about degradation/decay of the acetic acid in a more dilute form than the standard vinegar 3% level which maintains a pH low enough to thwart bacterial activity;adding vinegar to a mixture or carbonate and water dilutes the vinegar.

10/12/2017, 01:23 PM
If we were adding a mineral acid to the mix, we would indeed destroy some of the alkalinity. Vinegar is an organic acid. When added, it will decrease the alkalinity, whether added to the tank or to the supplement. The effect is small and temporary, though. When bacteria consume the vinegar (at that point, it's in the form of acetate), they release the alkalinity back to the system. The equations are in this article:


Carbon dioxide doesn't affect the alkalinity, although it's consumed to form carbonate alkalinity from OH<sup>-</sup> ions. That's how Kalk works as an alkalinity supplement. Our tanks never are particularly low on carbon dioxide, excepting dosing accidents.