how about a Specie Only Tank, I have a Bubbletip Only 10gallon, that is thriving. Daily feedings, and they split like crazy,mix up the colors, green's reds, oranges, and its something truly unique.
Protect ur anemones from intake tubes, by using a PCV pipe cut in half, siliconing it, and putting grates, kinda like a Oveflow. Put in ur Filter Intake (poss fuge), drill a hole for ur powerhead ouput ect.
For a 20, go with a 175w MH
Weekly 3-5gallon WC's
and keep your tank stable.
do a clown pair, one Black and White, one Orange,
I sure wish I had some pic's...i'll be transferring the 10 to a 12 AP with 70HQI tom..