Sometimes I'm overly detail oriented. (My husband says I'm anal-retentive but I think detail oriented sounds nicer.)
I was just thinking it wasn't a good idea to store a gallon of water in a warm dark cupboard while I only use up a tablespoon a day. In my neck of the woods that's how we grow algae (or poison our husband.)
I converted the gallon into fluid ounces and 5.3 oz is approximately two thirds of a cup is which is close to one 12th of a gallon and a quarter teaspoon is one twelvth of a tablespoon. Maybe. I hate math problems! Honestly, I'm not as stupid as I sound on this forum.
That's a good idea though, make a gallon and then use most of it in the bath. I'm just not sure how much is too much for the bath. Although if it's ok to soak in two cups of epsoms but you only eat a pinch of it, then I guess dumping in three quarters of a gallon of lime water to let's see, a thirty gallon bathtub...