Welcome to AA!!!
What kind of filter is that?
I would suggest using regular white sand (non-silica based) better for the tank and looks nice too. I use a product called natures ocean. I'm not sure about the "reef sand" crushed coral and coral sand tends to be larger and will trap food and particles and create problems. How much sand depends on the kind of filtration that you are look for and what kind of animals you plan to keep. I have a Deep Sand Bed of about 4.5" I don't know exactly how many pounds of sand that is but I would guess around 110-120.
As for the LR
you will want 1.5-2lbs per gallon so you would need 40-60lbs of rock in your tank. This again depends on the type of animals you are going to keep. The LR
will be your biological filter along with the sand.
Your tank will begin to cycle with the addition of some LR
or by using the Shrimp method.
I would suggest buy a protein skimmer for your tank. A nice HOW something like a Aqua C remora would do well on that tank.
Read these http://www.aquariumadvice.com/articl...php?fldAuto=2/
They will help you out a lot!