hi all, im doin some plannin for upgraden my feeder tank and was hope'n maybe some one could help me with an idea i had. im converten over to 30gal but its tall not long. i usaully preffer shallow but for now ill have to make due. anyways what i was thinkin was stacking some sort of material to make levels. they would all be open levels to allow alot of water to flow through but would offfer dem crabs as mutch surface area as possible. im gonna add a few peices of live rock in da hopes of keepin filteration as bialogical as possible and ill ad a hang on da back filter for machanical/some biological filteration. i was hopen to use some sort of man-made material for the stacks, somethin the crabs can hold onto, that would be light weight, but not float. im gonna check out da local hardware store but if anyone has any sugestions that would be great. thanxs-in advance.