"Sucked up inside an output" That sounds tough!
They commonly do this because of the high flow of filter outputs create a large buildup of biological residue that's a tasty snack for plecos. If it hurt him, he wouldn't go there.
very cool info...first time ive heard of that.
It happens A LOT with sponge filters. But this pleco must be more determined than most to swim into the direct flow of a power filter to get at it
On that note, what do you feed your pleco?
get some veggies in his diet...also, depending on the species, im not a pleco expert whatsoever, consider some driftwood if you do not have some already.
*edit sorry, i looked at the photo again and saw you have wood in the tank. still, jab a fork in some zucchini and sink it to the bottom overnight.
sorry, i think you said that in another thread. i would consider it, though...i know you are trying to avoid it. i know that i have seen algae wafers that have wood in them, so that is another option, assuming your other fish are not getting to them, first. may also consider lights-out feedings. ive always found my bn and L387 to be more active after lights out.
not sure if this will help to keep your bn from seeking additional food from your outtake, but it is worth a try.