I just built a sump out of a big rubbermaid container and I have a smaller clear one inside for the refugium. I would like to use it for pods, macro algae, & a deep sand bed for nitrate reduction. My question is, what kind of sand to use or should I use that mud stuff? I can't figure out which is best. Btw, I will also have a clip-on pc light for it, which I'm guessing is enough. ??