Here is one of my favorite analogies. . .
If you want to raise big, brightly colored, healthy discus it's best to raise baby and juvenile discus in a bare bottom tank.
Think of the tank as a glass feeding trough.
For best growth you have to heavily feed a diet of fresh and frozen "meaty" foods such as California Black Worms, frozen blood worms, beef heart, etc. These foods quickly foul the water. Food fragments can hide in gravel and under decorations.
Discus require very clean water. To combat the the dirty water from the "meaty" foods you should siphon the bottom of the tank and change at least 25% of the water everyday - more if you can. Wipe down the inside of the tank at least once a week.
Then, when your discus are done growing, you can put them in a planted tank if you so desire.
Carol