my ksb is about 3yrs old and 13 or 14 inches. ive got him in a 10-gal tank. he's been very restless the last few weeks, and he's refused to eat anything for the last month or so, which really isnt like him. is it possibly because his tank is too small? the last few nights, ive watched him crawl up to the top of the tank and crawl around the crack between the tank and the cover, just crawling around the edge for like 1/2 an hour at a time. is he getting too big for his tank or is this big enough?