I've never had a problem with mold. I use a 50/50 ratio and mix it in a large spray bottle. That spray bottle lasts me about a year. It molds?? I've never noticed a smell or floating things in it at all. My quilts don't come out different smelling or anything. I used the last of my current bottle last night and was getting ready to make some more. Should I add salt to it?? I just use stayflo and water.