I'm still working on my reef tank right now but I just got a new addition to my 30gal FW tank. My rope fish just hides at the top behind my emperor 400 filter. Is that normal??? At the lfs he was active and at the bottom to the mid level of the tank. Do I need some caves in there with him? I only have 2 plastic plants, 3 neon tetras, 1 betta, 1 pleco. Each fish is from 1-2" and the pleco is about 7".