If you have questions about Discus in a planted tank let me know. I have had my wilds for almost a year now in a planted tank. They have been spawing for months. The babies always get eaten by the tetras though. I actually moved the pair to a bb tank for a couple months, but they lost that lovin' feeling LOL. Put them back in the main tank and they spawned that same week! I really treat it the same as any other planted tank using the logic that what is good for the plants is good for the fish, but it is a compromise I must say for both the fish and the plants. Like the temp for example. Most Discus keepers want 85 to 90 if I recall. Most plants just can't take those temps too well so a compromise has to be make and the temp is kept at 83.
You may also find that with Discus you won't have to add as much KNO3 since they produce a lot in their own.