I'm not sure about the water changes, but I bet they'll help if anything. I would probably do 50% changes so you don't risk throwing the tank into a 'mini-cycle'. Also, I've read IAL have anti-fungal/anti-bacterial properties and that they can help with fin rot and fin regrowth. You can try it for a while and see if it helps, if not you can always go back to salt. Hope your fishy feels better soon.