I have a 10G tank with 5-10mm sized gravel (about 3 lbs), whisper 10 filter, 2 ghost shrimps, 3 neon, 2 white cloud mountain minnow, 1 bunch of anacharis, 4 plastic plants, 15W light, and an aerator.
The tank has been set up for 10 days, and I am doing 20% water change every other day...