As far as water changes go, you can't do too many.
As long as the replacement water has the same parameters, that is, aged.
The bacteria is in the filtration area, it is when you clean the filters with tap or hot water, that you can run into probs.
Use some of the tank water that you are changing, to clean them.
I knew some discus breeders, in Auckland, who IMHO without a doubt,
were the best discus breeders in NZ.
They did 50% water changes per day! !
Their fish were so respected by a fella called "Watley" ( heard of him), who chucked out his personal baggage,
to take back to the USA, his choice of fish from them.
Funny thing too, he said that our prices for discus were giveaway-prices.
Alan 104