sand in tanks?

for desert species i understand that you need to use sand, but would it still be ok in my glass tanks even though sand weighs more than the coco fibre substrate?

I have sand in my 5.5 gallon and its glass. A few inches of sand is going to be a lot lighter that filling it to the brim with water.

ok thanks, what type of sand should be used?

whats the sp.?

if it's one that just lives under rocks etc than desert sand, or dried out childs play sand / silver sand will be fine on it's own

however if it is a burrowing sp. then you may need to look into that excavator sand for pets which has come up in threads recently or do your own composite substrate using sand / bentonite clay

ok cheers