Its the crayola play sand. It comes in 4 colours blue,green,pink,purple. Pretty economical too at 12$ for a 20lb bag.
Use to be able to get it at most hardware stores but I can't seem to find it anymore so I don't know if the're making the product anymore. Been looking to pick up a couple more bags of green to do a new tank but cant find any in canada.
The red sand is just the stuff they sell at every pet store for about 7$ for a 5lb bag. The crayola stuff is a bit nicer IMO. The size is more uniform and required A LOT less rinsing than the fish store sand. The crayola stuff seems to settle down faster as well when it gets stirred up. The red sand floats in the water for way longer.