I have two tinfoils with my red aro. They are pretty quick and only lose the occasional scale. My new 6" aro is with a couple of angels, 2 blue gourami, a small severum and few plecos. It is working well now, she is swimming calmly back and forth and eats shrimp like a champ but I don't know how long this will last. I will have to remove these dithers eventually before they get eaten.