Reeflover,
NP! The other types of bottoms are a Deep Sand Bed (DSB) and a Shallow sand bed (a lot like a BB with a light covering of substrate).
A DSB is used by a lot of reefers. It usually consists of a sand bed around 4+ inches deep. When you have sand that deep the bottom layers become oxygen-deprived and different bacteria are cultivated (aerobic vs anaerobic). The third stage of your cycle (Nitrates) usually have to be waterchanged out or removed by some other mechanical means but with a DSB this bottom layer actually eats the Nitrates and converts them into Nitrogen gas which gets released as little bubbles. The downside is that you cannot have any sand stirring going on or the sand bed can release a lot of the toxins it stores/processes. Usually a mix of substrates or oolitic (sugar sized) sand is used for this.
A SSB is very similar to a Bare Bottom but with about an inch of sand. Mostly cosmetic or if you are looking for creatures like gobies that like sand. With high flow you can easily have sandstorms though.
I am actually fairly new to the hobby, only really been into it for about a year but I try to research a lot! There VERY many folks on here with tremendous experience, who can add loads more to this but I figured it is a start.
E