Adding distill vinegar through the Kalk reactor

OrionN · Jan 20, 2015

I need to add more Ca and Alkalinity to my 65 gal tank. I am top off with a kalk reactor. The reactor is feed using a dosing pump that draw RO water from a 5 gal can. I want to add a specific amount of vinegar to the RO water tank as I fill up the container every 5 days or so.
I do have a very well run and maintenance skimmer for this tank. Is there a down side to this? I think in addition to keep the Ca and Alkalinity up, this will also added organic into the water so that there will be an increase population of bacterial and other micro organism. This in turn feed the tank, and or also skim out with my skimmer.
Am I correct in thinking that adding acetic acid to the tank will not deplete alkalinity (not like adding Hydrochloric acid).
If my skimmer works well, then the net effect would be adding more Ca and Alkalinity. At the same time, this will reduce the nitrate and phosphate in the tank.

Any idea? I have start to do this with my 65 gal reef. It really boost my Ca and alkalinity.

Randy Holmes-Farley · Jan 20, 2015

Vinegar won't reduce alkalinity (at least not once it is metabolized), but there really isn't an optimal way to combine it with a reactor. It is best dosed from a settled reservoir of vinegar and calcium hydroxide (if you want the increased potency).

The main reason is you should not store highly diluted vinegar. It will be metabolized by bacteria and end up producing CO2. That will actually deplete the limewater in the reactor, rather than increase it.

I dose vinegar and limewater separately. The vinegar is dosed with a 1.1 ml per min BRS pump.

OrionN · Jan 20, 2015

My home DT is a 320 gal tank with frag tank and sump the total volum is about 450. The top off there is about 2 gal per day which I dose through the Kalk reactor with a Cole-Palmer pump. The reactor draw from a 1.5 gal reservore which fill automatically from my RO via a flow valve. I think this is an optimal way to add vinegar. I added 100 cc of distilled vinegar (5% acidity) to the reservore. Even if the resvoir fill continuopusly, I estimate that most of the vinegar would be gone in 48 hrs. This really boost the Ca/Alkalinity out put of the reactor. Certainly by meassure the Alkalinity and Ca, I can see a balance boost in the DT.
Does add CO2 to Kalk reactor deplete alkalinity?

Randy Holmes-Farley · Jan 20, 2015

I don't know how much metabolism of the vinegar will take place in 48 h (could possible be a lot), but watch for bacterial growth on the sides of the reservoir.

CO2 going into a limewater reactor will convert the calcium hydroxide into insoluble calcium carbonate. If there is enough excess calcium hydroxide around, it may still saturated, but you'll have to pay more attention to whether the solids remaining are useful calcium hydroxide or not useful calcium carbonate. An alk test on the product won't give a true reading since it will dissolve suspended calcium carbonate particles and count that as alkalinity.

Conductivity of the reactor effluent will give some indication of this, but I've not tried it with vinegar present to know what the saturation conductivity is.

OrionN · Jan 20, 2015

Thanks.
Sometime I overlook the simplest thing. CO2 and CaOH solution. Duh... I feel stupid

I am glad I asked.
I also have a choice in adding HCl instead of Acetic Acid. This I think will deplete alkalinity and change CaOH to just CaCl. at least I see this and elect not to use HCl.