Sir,
The one thing I can say about Discus is, don't rush things. Take the time to let everything settle in and don't make unnecessary changes if you can. If they are happy in the water you have, make efforts to keep it the same without letting it swing. I did drop the conductivity (the hardness followed) when getting them to lay eggs but other than that, patients is the key.
The only time I ever lost any Discus was when I'd try out something new and rush into it. It was always a disaster.
Also, when I first started I thought having the perfect water was critical, then experience taught me they are much more tolerant than I thought.
What I'm trying to say is, they will work with you, but don't jerk them around.