I have 12 discus in a planted tank. Keep the sand clean, do your water changes and it should go well. They grow quickly at first then they seem to slow down. Ihave them up to 5" but none have seem to have paired off. I use RO water and the fish just seem to thrive. They eat flake well, as well as frozen. I have had no problem whatsoever once the tank was established. (Idid lose 1 or 2 when I first started, but since then nothing) The 2 I lost were much smaller than the others in the tank, that may have been the cause I am not sure. Enjoy them, they are real relaxing to watch.