I have read about them being hit or miss, but I don't really think it is that. They aren't grazers. Mine is a fat bully. He eats with all the other fish, but will also swim around the tank at what appears to be random times, places, and goals. It then always turns into the same, 3-4 'pecks' into a clump of algae and off he goes again. I think our expectation of any of the animals to 'control' algae are that they live in it until it is all consumed leads us to fail when we view upon them as solutions. That being said, mine is still awesome...except for the fact he bit me yesterday.