In the 55 and 75 I used homedepots medium grade quickrete white sand. very minimal washing. Great sand and is of the heavier kind.
Thanks for all the input guys. If I wanted to go the black sand rout is there any one better than the other?
Black diamond blasting grit is way cheaper than "aquarium" sands. I get mine at tractor supply, 8 bucks for 50lbs. Just be sure you wash it really really well.