All purspose play sand from home depot. It looks nice but I had to rinse it for a long time. It's actually pretty nice I havn't had any problems with it getting sucked up my intakes.
Wrong, males have verticle stripes from the dorsal fin running down to the stomach. Females have dominate blotches that start from behind the gill to the tail creating what looks to be a horizontal line on the side of the body. Male= dominate vetical lines, females= dominate horizontal line. Also the size of the fish is important because if they are too small males and females tend to look similar. At around 4 inches male and females begin to change in terms of their markings. OP, could you take a side shot of this fish?