[jon.smolders]

For years I never used eggcrate (and I still got a lot of detris buildup under my live rock), but finally decided to add some last January when I set the tank up again after we moved. Instead of doing the whole tank bottom, however, I cut out small chunks and strips (2"-3" pieces) and placed them under the parts of the rock that were touching the bottom. This gave the rock extra support, but left very little eggcrate to look ugly or catch detris. My sand is only about 1" deep... if it were deeper I would add short PVC pipe legs to the bottom of the eggcrate pieces to raise the rock up a bit so it wasn't buried in the sand quite so much. Works for me... I don't know if it benefits the tank much or not, but I havn't had any problems so far.