I have one now for about 3 weeks. Mine eats algae and will sometimes munch on a piece of zucchini. I've tried other vegetables like broccoli stems, carrots, and spinach, but it doesn't seem to go for them.
I have also read that it will accept various fish food, but mine ignored flakes, sinking tablets, and sinking algae wafers. The last was a bit of a surprise.
It hides among rocks especially during the day and is more active at night.
I quite enjoy it. I'm actually planning on getting a couple more.