I've been putting some serious thought into what I should do about the rhinos and the tank. I doubt the 50g will be enough for them for much longer, ecspecially the way i have it aquascaped since it is infact a reef. I did some rearranging today and made significantly more room for the rhinos. The torch and bubbles are growing quite large and taking away from alot of the substrate room, so i decided to take one of the bubbles out and rearange things a bit. Hopefully I can set up a 120 in the near future for these guys, but for now im just going to keep a close eye on everything. The tank is plumbed to another 50 which i use as a sump, so there is substantial water volume for the largish bio-load, its just an issue of space now.