Using General Cure for discus fry?

[MoanaVic]

First batch of fry ever are now about 16 days old but a few died yesterday. I read from a professional breeder about medicating preemptively to avoid the “30-day die-off” that often occurs. I am considering a dose of General Cure but the instructions say dose once, then again 48 hours later, then a 25% water change after another 48 hours. But I am already doing daily 70% water changes. Is anyone using General Cure or some other medication in their fry tank and, if so, how are you managing your water changes?