Substrates for a Nano Reef?

[redwarrior]

I'm trying to choose a good substrate for a nano reef tank. I'd like to use live sand, but I'm not sure if I should go for something very fine or something a little more chunky...Here are my top 2 contenders so far:
A fine, live reef sand
-or-
A little grainier with a tiny bit of pink to it
I'm wondering because I plan on adding 2 koralia nano powerheads to this tank, one on each side for good flow for corals and I wouldn't want too much sand shifting around.
Ideas?

 

[keith burn]

imo go with the fine
It will not hold junk in it.the biger the more it will hold.
The more jumk that is in it the more treble you will have with water lvl's going off.
And in a nano it will go off fast.