i bought a pleco and jack dempsey to put in my growout tank in the 55. the fish in the 55 is an oscar and a convict. they dont fight alot. my oscar is 4.5 inches big. the pleco and the dempsey is about 3 inches each. when i put the pleco in my oscar almost ate. but luckily there was the nemo doll which he is scared of so he spit the pleco out. i placed the pleco in those betta bowls and made it sink to the aquarium with the dempsey. when i looked at the pleco his back tail is wounded and most of the fins on the top are gone. what should i do. he healed a bit from yesterday. also i put a cucumber in there but it doesnt eat it.