just wanted to say that i never used airstones keeping discus
my recipy to happy discus is this: (every step extremely imprtant if you follow this)
1. full CO2 system, co2 at 6.5-7ph
2. lots of live plants,
3. bright lights (in two shifts if possible)
4. places for discus to hide from lights
5. peat moss in bottom half of pots for plants and ph reduction
6. strong self made filter with a spray like bar for intake to cover wide area near bottom
7. vaccum gravel once a week
8. change water once a week.....
that's it