personally for a shoal of pygos, I would do an amazon style "biotope' with reddish sand and plants, and some cool murky looking driftwood. I'd make it look like a flooded forrest during the wet season.
I agree with hunter. I went with 30lbs of black and 30lbs of dark blue for my 125 red Belly tank. Seems like a waist because now Im converting it to saltwater and all those rocks are going bye bye.