Thanks for the advice. The pleco is under 6 inches...he is probably about 4 1/2 inches long. I feed my fish tropical red flakes, so their poop is normally red. I give my pleco algae wafers, but he never seems to eat them and he doesn't seem to be growing and I've had him for 6 months now. I went to do another water change and noticed that the water was quite cold. I realized that the heater was broken and that was probably why they were pale and acting funny. I bought a new heater and they seem to be acting better, although the waste is still excessive; I guess it's all from the pleco? I don't know.