What kind of plec is he? Most are primarily vegetarian. I have bristle noses and they eat; algae wafers, peas, green beans, broad beans, sweet potato, broccoli, some flakes etc. As long as you give him plenty to eat with lots of variation, keep his tank very clean with lots of regular water changes he should grow well.
What you feed your plec depends on what type of plec it is- they can be anything from insectivores, carnivores, herbivores or omnivores- some are even wood eaters. A good varied diet is the key to good health, also, some plecs dietry needs may change as they grow (for example, common plecs are omnivores although their diet is very veg/algae orientated in youth, as they mature towards their max size their diet becomes more protein orientated) .
If you do not know what type of pleco you have, it is important to ID it as soon as posible to figure out what is best for it habitat and dietry needs wise .
cheers guys,
iv not long had my pleco, little dave, he's justa a common pleco and iv been wonderig what i can give him.
will the other fish not try and eat the beans etc if i put them in?