I have two 44 gallon Brute cans in my mixing station. I use the R/O can for auto top off and also transfer that water to my second can where I mix it with salt (Reef Crystals) for auto water changes. I want to add kalk to the first can for dosing via auto top off, but I am told that this makes the R/O water unsuitable for subsequently mixing with salt in the second can, which implies that a third can is necessary to accomplish kalk dosing. Three 44 gallon cans will take up too much space. Any thoughts on how to avoid the need for an additional can?