So, in our videos we use 5 gallons buckets of chunky slime, which usually comes out to:
- 10 boxes of white cake mix - about 1/3 or 1/4 of a 5 pound bag of flour - about half a pound of two different types of oats - (I couldn't tell you how much water or food coloring is used, have never measured those things!)
So if what you are using is straight cake mix and water and in a one gallon bucket, but you want to keep it smooth and thick....I would think 3-5 boxes of cake mix per slime.
***This is a guesstimate***
I would always keep multiple extra boxes on hand in case you add too much water!
About 3-4 cups of water per two boxes of cake mix usually got it to a not overly thick or watery mixture for me. As I went bigger and bigger, it just became guess work...just put in the cake mix, and add a cup of water at a time, and mix it all up until you get the consistency you want. That's what works for me anyways...