The breeder net I had was designed to hang by the edge of the fish tank. Apart from preventing the tank lid from closing properly, this setup was also keeping the breeder net's top edge high up above the water line, which was leaving little space for the fry. So I made this float so that the fry net is hung with it and afford the fry more swimming space. Might require the use of zip ties to attach properly.
This float fits a 17cm x 13cm breeder net but can be scaled as needed.