thought i would update how Prince is doing..
he's not a big fan of carrots, one of the pieces of carrot surfaced a couple days later.. but i put 3 in, so maybe he just got full?
anyway, we put the piece of grapevine wood in the tank, at first he didn't care about it, just hung out on his rock. but a couple days later both Prince and Houdini (marble x RTC) have decided that the wood is home and seem to actually like each other.
And Prince has become more active during the time the lights are on recently, i don't know if he's just getting used to the tank, or the wood made a difference.. but he seems more at home and more confident now.