I’ve been thinking about breeding my Cory catfish, but need to build a good nursery for the fry. I cannot do a mesh fry separator because of the shape of my tank’s lid and my dual filters. So, I need to get a small tank I can put the fry in until they grow up. I just don’t know how to set up a good nursery. 1. How big should the tank be? I am only breeding one pair, but I may breed more. 2. Can it have substrate? If so, does it need to be sand? I have little experience with sand and am not sure how to clean it.