Soo, my little sister wants a Betta fish, and I was going to just buy a small tank and the fish. But then I got to thinking, "I can do better than that." Well, I saw a post about an algaescape with micro crabs, and I had the idea that I could perhaps do a tank with a carpet, a few crabs, and a Betta. So, is this a good idea? What kind of substrate would be good to use? And are the crabs a good idea?