We have put together our thoughts on Kalkwasser for those that dose it. We use this on our own tanks and you’re welcome to try it on yours. Kalkwasser historical dosage (from Marine Aquariums by Jeffery Kurtz): 1-tablespoon of powdered Kalk per 1-gallon RO DI H20. Below then is our recipe with added vinegar and why. We also produced a video on this topic and I have put that at the end of the post here for people to see.
In my case the dose is 2 tablespoons kalkwasser to 2 gallons of H20.
Vinegar Dosing for my 2-gallon Kalkwasser mix (by Ryan Speltz, DVM): 1-teaspoon kalk per 15mL clear vinegar.
In my case that is 2-tablespoons kalk to 90mL (1/3cup) clear vinegar; add to 2 gallons of H20 after dissolving the kalk in the vinegar.
This method allows for:
1. Calcium ion (Ca++) higher concentration because you dissolved it in acid vs water and achieve free Calcium ions.
2. Vinegar binds C02 and hence no loss of Calcium to calcium carbonate precipitating out.
3. Makes for faster and easier dissolving of good lab grade Kalk like BRS product. This helps keep it in solution better and keeps the tank clear of calcium carbonate issues.
4. Using only clear 5% vinegar is cheap and safe for the reef at the above dosage and does not affect pH.
This is simple chemistry folks and can be explained in more depth if one likes, but really this is a simple chemical reaction. I have been using this along with others in my field and although it is not done commonly around the MN area I think the reason is due to lack of chemistry knowledge and fear. To reduce your fear you can start out with less vinegar and watch your tank for issues. Always check your Calcium, Magnesium, pH and specific gravity values and see how you do, I am sure you’ll like it.