I am thinking I need a medication tank as I have a yellow tang that I believe has a bacterial infection from what I am reading. Not sure I am going to be able to get this done in time for my tang but hoping it can hold out. When you have a medication tank can it also be used as a quarantine tank? Would this tank need to be online all the time or filled when needed with tank water or fresh salt water? Have been pretty lucky with my fish to this point but feel if I am going to stay in this hobby and have more fish I need to do this both for myself and for the fish.