Planted Tank Guru
Join Date: Dec 2017
Location: Elk Grove, California
Angels, like most cichlids, very in behavior.
You will have one person say they have had neons with their group for years without predation and another say that the Angel ate/harassed them within moments of being put into tank.
My Angels and discus ( and my 6-8 inch geophagus-- have you seen a geophagus mouth open wide? Could fit a 4 inch tetra in there) ignore smaller fish. Ive had the same group of rummy-nose and green neon's with my discus for several years. They co-habit peacefully.
What temperature do you have your tank set at? Most Angels are kept at around 78-84 (84 being wild Altums, not scalare). I think that is a bit high for live-bearers long-term.
I would try a group of Rummy-nose, green neons, or Lemon tetras-- all these can take higher temps required of Angels.
You could also confirm the sex of your Angel and get a male or female to get a pair. In that case, I would only add bottom fish ( or none at all).