I don't recall if this pertains to the salt/heat method but I've always been told to turn the lights out when treating ich. Maybe somebody can clarify?
Good Remember, once all the salt is dosed you have to be patient, even if it looks like it's getting worse.. The heat/salt treatment will kill the parasite once it's free floating so there is nothing you can do to remove them from the bodies except wait for them to complete the life cycle.
My platy fry have it right now and it's frustrating but I'm just keeping the temp high, salt at a proper concentration, and vacuuming the gravel every chance I get to remove whatever spores I can.