It's actually play sand substrate...its really nice actually, not white but not dirty brown...gives it a nice color. I took the picture with my macbook so that should explain the upward angle...
the hardest thing was to make it so there was something out of the water for my red claw crab to get out of the water, thats why there is 2 pieces of wood stacked in the right corner...
The girlfriend issue was extremely hard, we had a big blow out fight and she realized she wasnt going to win (me selling the tank) so she backed down and compromised, I wish the conversation could have been recorded, a fight about fish....lol