The Congo puffer or potato puffer is a freshwater pufferfish found in areas of the Congo River in Africa. This is a freshwater puffer and does not require the addition of salt to its tank. What is essential, is the provision of a deep (2-3″) bed of sand as substrate. This will allow the fish to exhibit its natural behavior. (Hiding in the sand) Provide additional cover in the form of smooth rocks (interestingly the puffer will often attempt to mimic these), and driftwood pieces. Plants can also be used if you wish.