Changed my tank from gravel to black sand about 2 months ago. In the last week I have suddenly started seeing what looks like small worms all over the tank. As I have seen similar hanging out of the BristleNose Pleco's rear I assume it is his poop, and they are known for this, BUT I swear I have not seen it in the aquarium before 3 days ago. Now it looks like a fecal or worm explosion. Cleaned the tank yesterday and it looks like I haven't ever cleaned it. Just wanted to verify that is what his feces looks like.