Hi Dean,
The amount of kalkpowder you need to add depends on your calcium usage rate. One gram of kalkpowder will raise calcium levels by around 5ppm in 100litres of water.
So if your calcium utilisation rate is say 30ppm for a 600 litre tank per week, you need to add (30/5) *(600/100) = about 36g of kalk powder per week (or around 20litres of saturated kalkwasser per week)
Now if you want to dissolve the kalk powder using vinegar you will still need to use the same amount of kalk powder you have calculated above. To fully convert 1 gram of kalkpowder to calcium acetate (using vinegar which is about 6% acetic acid) you will need to use about 27ml of vinegar per gram of kalkpowder (or about 1 litre of vinegar for the 36g weekly requirement in the example above).
The obvious advantage to this method is the smaller volume of liquid you will be adding (1litre vs 20litres), safer as pH will be slightly acid as opposed to highly alkaline, and you can add this quantity relatively quickly if you need to. No ionic imbalance with long term use.
Possible disadvantages - Won't get the benfits of phosphate reduction when using kalkwasser. Also kalkwasser is self-purifying (all contaminants precipitate out due to the high pH) but if you use a low grade kalk powder with the vinegar method you will be adding contaminants.
The other thing to bear in mind is that acetate is a carbon source. It can be converted to alkalinity equivalents, but some will also be utilised by bacteria for growth. Now I am not sure if that is a good thing or bad thing, but to me it seems similar to the vodka method and I would therefore be quite wary in adding such a huge amount of a carbon source to my tank.
My opinion - If you want to use kalk then use it as kalkwasser - has a lot more benefits. If you want to use something to raise Ca easily and quickly then use a calcium chloride based product rather than a mix of vinegar and kalkwasser. Only negative is a possible ionic imbalance (chloride increasing realtive to the other major ions) but this is easily corretced with regular water changes (and there is really no evidence that this is actually a concern anyway)
We spend lots of money on our tanks and spend good money on top quality additives. Now why would someone then want to add an unknown factor (vinegar) to the mix.
Anyway I hope that long ramble makes sense.....
.
