First off, this isn't for me so my tank info won't help. My girlfriend's parents have had oscars for well over 10 years. Recently they had theirs die and they got a new one. Being that I'm into the hobby now, I asked some basic questions and it appears they got a common pleco which is quite old. Well, they have algae growing on the glass and I have read that the pleco will pretty much stop eating it when it gets 'older'. So, it would appear they need new algae eater. So the question is, what can they get with an oscar and a old pleco? The tank isn't your standard 55g long. If I recall, it's more tall than long. I'll be going there on Friday and will do a water test and measure the tank. Thanks.