I tried it in a 10g nano,,,, I only used 3/4 of the recommended dose and my xenia suddenly died,, could be a coincidence of course,,,, the zoo's and open brain in the tank were fine.
NO medications are truly reef safe. Are you saying you've dosed already? I hope we can discourage you sufficiently from doing this.
Also, treating a display is strongly discouraged for many reasons, not the least of which is killing off beneficial bacteria, or exposing fauna that will be harmed by said product. Also, dosing is far more exact in a hospital or q/t system.
Used it for cottonmouth on my GSM clown, took care of it in 2 days. Only doese 5ml in morning in my 55g. I had a BTA, Silver pulsing xenia, mushrooms, devils hand leather, sun polyps....only thing i noticed is the BTA would close up about 10 minutes after putting the Melafix in tank. WOld stay closed for about 1/2hr-1hr