Originally Posted by
salt monger
http:///forum/post/2461144
with all the money you're gonna eventually spend on the tank, why skimp on the sand, it's the foundation of your eco system..... use the right stuff from the ground up is my opinion....
Skimp on the sand? Are you knocking bare bottom tanks?
Seriously though, sand like everything else is all a matter of the right use for the right application. Everything has its strengths and weaknesses.
As far as materials:
Silica-type sand is super cheap (unless you get black sand, you'll pay extra for that), but has no real additional benefits. It's just sand. Not bad, but does little extra for you. And you'll need to put more work into buffering your tank.
Aragonite or other calciumy substrates will help buffer your tank. If it's oolitic, all the better, because it will be less likely to lock up and pack.
Crushed coral/gravel... not really very good choices mostly because of cleaning: stuff gets caught up on it and unlike sand you can't really do an effective surface siphon.
As far as setup:
A bare bottom tank can work great for SPS tanks: you can have blisteringly fast flow without much worry of a sandstorm (plus, no falling powerhead disasters)
A shallow sand bed will give you that natural look, but do little for you. Not much of an eco system really, and not really any denitrification either. On the other hand...
A deep sand bed can help lower your nitrates, and you can have a decent little sandy ecosystem. BUT... some people's crash after a few years and wipe the tank. It's still not exactly clear why, or how to husband it so that it won't happen, and it doesn't happen to everyone.