[Sable]

I have a 45 gal (30w x 22h x12d?) FOWLR tank set up now, I just got a testing kit and have several issues. One issue is the abnormally high nitrate (actually off the chart) and the abundance of red algae in my tank and in the crushed coral on the bottom. My question is this:

What is the process, and is it worth it to remove the crushed coral from my tank and replace it with sand? And is a 20 lb bag of sand enough for the size of my tank?

I don't like the look of the crushed coral, but this was all that was available when I started the tank. I checked out International Marine Fish and they have Bahamas Oolite live sand (20 lb. bag for $40.00 w/ free shipping).

Any and all ideas and help / suggestions are appreciated!

~John