tkos hit that one on the head.
Ich has a 3 stage life cycle and the meds basically only kill them during the freeswimming stage (they are pretty much encysted the other 2 and the meds can't get to them). There's a great article about ich here: http://www.caloriesperhour.com/fish/notes_ich.html#salt . It explains things a heck of a lot better then I can LOL
I'm unfamiliat with Nox-ich, but it does apparently contain malachite green which is one of the chosen chemicals for treatings ich.
Ich has a 3 stage life cycle and the meds basically only kill them during the freeswimming stage (they are pretty much encysted the other 2 and the meds can't get to them). There's a great article about ich here: http://www.caloriesperhour.com/fish/notes_ich.html#salt . It explains things a heck of a lot better then I can LOL
I'm unfamiliat with Nox-ich, but it does apparently contain malachite green which is one of the chosen chemicals for treatings ich.