I just have a few emerald crabs in there. I actually used them to cycle the tank when I first set it up about 6 months ago. I just let the algae grow in there so that they can use that for food, and throw some algae/spirulina based food in there like every few days or so. When I change out the water in my reef tank, I do the qt as well, and put some of the water from my reef tank in there to try and keep them close in terms of water conditions. It's a bare bottom tank, however, I did use a few pieces of base rock (arogonite) just to kind of help with keeping the buffer at a good point to avoid fluctuations in pH since it is only a 10 gallon tank.