Join Date: Oct 2010
Location: Victoria, Australia
Being algae eaters that graze constantly, my otocinclus used to poo everywhere. I only had two, but because there was so much soft algae for them in that tank, I would have to siphon on an almost daily basis.
However, their bioload is nowhere near as massive as something like a pleco, in fact it's fairly low. Even with that much waste I never saw any spike in ammonia readings.
I have never owned cories so don't have any experience there.