Purchased a couple of these about a month ago, and I must say they are impressive at keeping the algae at bay in my tank. They are still small at the moment (about an inch in length) I love them as they are active during the day and great time wasters! I have noticed however that they can be territorial, I guess I may have two males?? I have an adequate tank for them being 180 litres and lots of rocks for them to hide in. Anyone have any experience with these? If you have a well aerated tank I do recommend them