Thanks firenzenz,
They have 2 large bits of wood in the tank. have been monitoring the water toxins all reading 0 as its a large tank with hardy any fish.
did a reasonable water change last night.
there has been a lot of algae, both green and brown as we recently got lights for the tank, we got a new little girl in the weekend and she's been doing an amazing job cleaning it up.
normally feed flakes for the other fish, and vegies and fruit to the plecos.
I got them spirilina discs but after a debate with our LFS fish guy decided they are just fussy as they dont touch them. so they are feed broccoli which he normally loves, and sometimes a bit of apple, haven't given him much zucchini with it not in season.
I did notice a large increase in pleco poop when we got the new little girl, so they might not have been pooping for a while.
tank temp is normally 25 deg C.
at least we now have him separated so we can monitor poop levels if any, and no food.
will try raising the temp a little tonight.
many many thanks
Cayley