the foam goes right on the tank! It comes out like a big snake, then you let it expand a bit, then you start breaking it up by poking it and moving it around. As it starts to harden you pop any large bubbles and when it gets a little harder than that you smash it down to make sure it sticks to the tank and to give it a "natural" rock texture. It was pretty interesting to watch her do the work...it's all about timing, as it is to sticky to work with part of the time and then to hard to do anything with after awhile. You have to be quick!

We put blue painters tape over the bulkhead openings and then just didn't put foam right across them. Let's put it this way though...those bulkheads are NEVER coming out!!!!