Is that your Pacu in the 125? Looks like the tank is way to small for him. Need to step up to a 300 +.vaine111;2831355; said:had 2 and 3 oscars. along with countless other tankmates. if you are really planning on keeping all those fish i suggest a minimum 300 gallon tank. or just be like my buddy and practically take the fish to the point just before they just die from starvation before you feed them and they should fit in maybe a 120.