Brasil Reef - Fórum de Aquário - Aquarismo - Marinho, Corais e Água Doce

If you use Acetic Acid from a chemical company, buy a concentration of 5 per centAcetic Acid in water (an aqueous solution). If you use Distilled White Vinegar from the grocery store, look for an "acidity" of 5 per cent on the label. Never use any colored or flavored or Apple Vinegars.

"Kalk" powder is either lab-grade Ca(OH)2 (Calcium Hydroxide) from a chemical company, Kalkwasser Mix from an aquarium supplier, or Pickling Lime from the grocery store. It's all about the same. Use 1/2 teaspoon of the powder per quart of solution -- maybe a bit more if you use Pickling Lime from the grocery store, which is less Calcium by weight than the other sources.

Some words of caution, especially for any reefkeeping newbies out there -- If you are using Vinegar in your Kalk mix for the first time, I'd start off with 5 ml per quart at first. If you find you still need to get more Calcium into your tank per unit Kalkwasser, work up over a couple of weeks to a max of 12-15 ml per quart (the stoichiometric amount for Carbonate as recommended by Craig Bingman), or if you are feeling brave or really need lots of extra Calcium and de-Nitrate action as I do, a max of 24-30 ml (the stoichiometric amount for Bicarbonate, which I use).

Don't go whole-hog on the Vinegar from the start until you are sure your tank needs it and will take it without experiencing radical changes in pH, Calcium, Alkalinity, Magnesium, and the health of your critters and your Nitrifying bacteria. Measure ph, Alk, Calcium, Magnesium, and Nitrates with Salifert kits as you work up to more Vinegar.
Observe your livestock, especially if you have any really delicate corals or fish, to see that they behave normally as you use more Vinegar.

My tanks have very little evaporation, so I have to use lots of Vinegar to put in lots of Calcium with very little makeup water. If your tanks have tons of evaporation, use less Vinegar per volume since you don't need such a high Calcium boost per unit of Kalk water.

As with all things reefing, go slow, observe the reaction of your tank to any changes in what you add every week, and understand what and why you are doing. I don't want anyone coming back here on the board and blaming me for their fish that died when they poured 1000ml of Glacial Acetic Acid into their 55 gallon tank!

My methods are safe for me in my tanks -- your mileage may vary, so use due care.