have you had any hair algae/other algae issues on the egg crate yet? prob still too early for that yet though.
i have virtually perfect water chemistry, and same goes for others i know who use egg crate in their fragging area, but it seems everyone gets some nusance algae that developes on the eggcrate.
i've found myself taking the eggcrate out and just putting frags on the sand bed so my conchs can get to them and clean them up. most of my snails seem to have a problem climbing up the PVC, then getting onto the eggcrate and not falling off.