ok here is some photos
this is 2 of the 3 150gal that my background will go in
took a little different approach to the back grounds by cutting the foam into individual "bolders"
carved the edges
I had started the background and did only 4 feet last week to make sure it would fit ok so i had to come back and do the sides and the other 2 feet.
just a note if you do it this way you will only need about 5' 6" inches of foam for a 6' background the inside on the tank is about 5'11" and you will use about 5" beteen the "bolders" in space this is why I did it in two parts.
used a mop like paint brush for the first coat
I found a empty one gal milk container worked best for me to mix the cement just cut away the front
now just let it dry overnight
I was going to lay some moon sand in the cement but it didnt look good so i am going to coat over it and just let the algae grow.
it's good to mark top and sides to help with the jigsaw puzzle when down ... mark the back not the front as I show in the photo the front gets covered with cement .....yeah was late and I was not thinking