Weekend Wonderings: Adding and removing from the water amount

When we’re adding or removing water soluble ingredients from a recipe, we tend to remove or add to the amount of water in the product.Let’s say we have a recipe that looks like this….BASIC LOTION RECIPEHEATED WATER PHASE74% waterHEATED OIL PHASE20% oil5% emulsifierCOOL DOWN PHASE1% preservative…and we want to add 0.5% allantoin, how do we…