That's not a very large tank so you won't need a lot of medicine and you probably won't need to spend a lot. When you add the medicine you may want to remove any ornaments because it may stain them. I love your fish! Neons are beautiful and so are the sunset gouramies and x-ray tetras. do you have a heater? Because you need one with these fish. Anyway hope this helps.
ryanp13
