I'm currently growing 11 discus in a 75 BB tank. I started raising them from 2.5" - 3" mark about 4 months ago. I got discus from Al Castro and Discus Hans, gave them a good quarantine and mixed them together.
Tank has two sponge filters and Marineland hob filter. I do water changes every day about 30 - 50%. I feed them Beefheart - twice, flake food, tetra bits and fdbw ( 5 feedings a day) tank stays clean. Have a group of endlers to do the clean up job. I have really good results with this routine. Hope that helps.