kalkwasser and vinegar

[Aquattro]

I've done this for years now. I find it allows the dissolution of more CaOH which is at the very least more efficient. The theory behind it is to have the vinegar act as the carbon source in the reaction of CaOH to CaCO3. It's hard for a hobbyist to be able to notice whether this provides more Ca and alkalinity over straight kalk, but I do have less "sludge" when my top off container is empty.