[oregon aqua]

for co2 your going to need a good reactor i suggest this one http://www.barrreport.com/articles/3444-dual-venturi-diy-external-co2-reactor.html

it should be good for a 180 gallon maybe go bigger on the tube part? then a good regulator/solonoid combo like a Milwaukee on a timer.

 

[oregon aqua]

I like the second one.

here are some articles about setting up hardscapes that i like.

http://www.adana.co.jp/_e_howto ada setup

http://www.aquatic-eden.com/2006/11/golden-rule-of-aquascaping.html golden rule article

Personally to simplify the golden rule with no math, nothing in the center, only one focal point, this keeps your eyes happy and you want to look at the tank longer and it looks more natural.