Yup you need algae. Also try to feed as little in the way of protein foods to them, and give them veggies that are pretty high in roughage... good for their digestion processes.
Plecos in general will suck on slime coats, sometimes because of malnurishment, others because they can. There are a lot of fish that are still and won't move when they do it... that's why they are a poor choice with bichirs.
Plecos in general will suck on slime coats, sometimes because of malnurishment, others because they can. There are a lot of fish that are still and won't move when they do it... that's why they are a poor choice with bichirs.