If you have a injured, weak or sick fish and you need to separate him form the others this floating tank can be placed inside the aquarium. The part itself is designed to float so you can put the fish inside. Due to the design the water will be exchanged like in the rest of the aquarium. This helps to keep the fish from stress and accelerate heeling. Note: Infectious diseases should not be handled with this piece since it will not remove the infected fish from the aquarium leaving the chance the disease spreads.I have not yet printed one but due to the calculations I have done they should float perfectly the bigger one even better then the small one. Also when you print them with the side with the holes in it on your printerbed you will not need any supports to print.