[bignick]

I'm big on the holw pillar thing and the best advide i can give you is to not drill your rock. Whats your hurry? Take your time and slowly put the pillars together. I found Tonga to be some of the best rock for doing pillars and such. I actually started out with pillars and switched to islands. To make more room for coral. But seriously i thought about going down the drilling and acrylic rod road but after some patients and a few (cases) beer i ended up with a real nice aquascaped tank. If patience wears thin then go the acrylic road but it will be very rewarding in the end if you build a solid structur with just the rock.

JMO

You ned to do what works best for you.