last night i found what looked like a single thread of spiders web in the guppy tank, on closer investigation it was coming from the b/n that is in there, it was about 40cm long that i could see

Help, what is it, probably a really stupid question, but i want to know

the b/n looks well enough, the water is good

From which part of the bristlenose was it coming from?

It's not a stringy poop is it, i've seen some real long ones from my standards and GBA.... if not BIIK (Bu@#ered If I Know) scratches bald spot on head & ponders...

looks like long slimy poo,

diet is ok, wood spirilina discs, all the growth in the tank, i just dont know

You could try them on some shrimp pellets, thats what my GBA eat first between that, Nutrafin bottom feeder tabs (second to go) and pleco chips (think they have spirilina and wood in them) and they have a chew on the driftwood. I do recommend feeding shrimp pellets in a container of some sorts, i use a rectangalur glass dish about 80mm tall so the shrimp pellets don't end up in the substrate.

Are you feeding them some veges like courgette or cucumber? my GBA go through a piece about 40mm long cut in half every day.

I've seen this before but not on the ancistus sp I'm breeding at presant .

It could be diet ?

there feed dayly on blood worms , cucumber or courgette and theres a lump of wood they rasp on as they like.

note there is always food in the tank

B/N like a highly fiberous diet, and their exrement tends to hold together in long strings if they are getting the right diet. (as do all plecos)

Dont worry ! Your fish is eating well and just doing it's thing.

Alan.