We've had a common bristlenose for 3 months and we never see him cleaning/eating algae. He's about 2.5 inches and has a ton of bristles. He's in a 40 gallon tank with a 10 inch common pleco and they are often in the same cave together, so he is not getting harassed. The other fish are various tetras, 2 albino cats and a few otos. There is driftwood, a tube and a cave for him to hide in. He usually hides behind one of the plants. We have never seen him eating the algae wafers or veggies or even the shrimp even under blue light with all the room lights off. Any suggestions?