I had one she was healthy and active. I got two more to comfort her. They do really well in groups of 3 in my experience. It worked with my bronze cories who are practicky blind from albinism. I love my two new ones they are still warming up quote small by the species standards. In my experience 3 works for schools.
My first CPD is a year old my other two are a week. I have had my fish for a while in a community tank. I have found 3 works well for cories and CPDs. I am right how many of you keep them. I only had one and I tripled the amount.