One of the stores we frequent has a very large tank that is completely set up with imitation coral. It is amazing how real the coral look. The one thing you have to be concerned about is algae. Since it is not living coral there is the likelihood that algae will coat the imitation coral so you will need to continually clean it.
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72 gallon bowed 150lbs LR 60 lbs LS
2 Percs
1 Chevron Tang
Hippo Tang
Six Line Wrasse
Coral Banded Shrimp
Cleaner Shrimp
Starry Blenny
4 Lyretail Anthias
Long Polyp Toadstool
Montipora
Long Tentacle Anenome
Short tentacle plate
Pulsing Xenia
Green Star polyps
Frogspawn
29 gallon
2 Clown
1 Coral Beauty
1 Fairy Wrasse
24 FOWLR
Dwarf Lion
125 gallon African Cichlid Tank
http://home.comcast.net/~pizzal/index.html 
"The more you learn, the more acutely aware you become of your ignorance"