I tried this-- the food coloring stained the styrofoam a beautiful purply red. THen I could n't see the water filling up at all. I was so disappointed. I fill it now when I turn the eggs by hand . Without a turner, it is easy to part the eggs and add water. I"m sure it is not so easy if the turner is in the way.On one of the other threads food coloring is added to the water, makes it easier to fill.