Hi: I am wondering how much kalkwasser to add to my top off system? I have the Tunze kit 68 with the calcium dispenser. I was told that the rule of thumb was 1tsp per gallon to start out with.... The question i have is if the rule refers to gallons of top off or gallons of saltwater? This morning i added 1 tsp of kalwasser and was going to add from there. Anyways should i be referring to gallons of ATO water or gallons of saltwater? Thanks