Sand Bed ?

[SnEaKyPoLoCk]

Emo and I started my 55g tank with about a 3.5in sand bed. Is this too much? What's the difference between a shallow and deep?

 

[a1amap]

http://en.wikipedia.org/wiki/Deep_sand_bed
http://www.reefs.org/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=28&t=000024
http://www.ronshimek.com/Deep Sand Beds.htm

You will find opinions very greatly on the subject.