As far as 80% water change per week, is that in one shot? or continuous throughout the week?
That would be all at once. I have been blessed with really good water quality and it doesn't seem to affect the fish at all. They start eating within a couple of hours after the exchange.
What about the salt? Are you going to prep some water in advance? What about changing water quality parameters too quickly? Any possibility of accumulation over time?
Do you think there may be some induced stress on a repeated basis?
Look up what a sine wave is and apply this cycle to it.
