Many will tell you that a DSB for a nano is not big enough to truly do the work. It can still act as a nutrient sink if improperly maintained. This can help a little in the short term but can crash the tank in the longer term. The nano I am working on now will have a sand bed, but it is critter driven (watchman goby / pistol shrimp pair) and not filtration driven.
Good luck.
Ray
Good luck.
Ray
