see that is what fishingout was talking about, you will need the larger tank asap with those future monsters "a few years from now", you say you have a 10g soon to be a 55g but you are going to need a much larger tank than this for these fish for 2 balas a pleco and an oscar you would need at least a 120g tank (you could probably add another bala if you got this size tank), also plecos get huge and are big waste producers so if you got it because it will "clean" your tank then i would go return it because simply keeping your water clean will be more efficient at taking the algae of your glass then any kind of pleco will