The Discus tank probably has to be fed.
How old and stable is the CRS tank? That will probably be fine without food for a week. or maybe just fed once or twice while you're gone.
The only reason i'm interested is overfeeding us usually what screws us while we're gone, it happened to my 55g a while back, GW, 2 GBR pairs dead, and tons of other fish. Now I don't worry about when i go away for a few weeks on end. I'm all algae eaters now!