What odd choices of dither fish have you tried? How did it work out?
Yesterday I bought three beautiful, juvenile marbled angelfish--at Meijer of all places--to increase the size of my small angel gang and hopefully decrease aggression. The new angels are about half dollar sized and healthy looking. When I introduced them to my current quarantine tank, a lightly planted and snailed 29g THEY FREAKED THE HECK OUT! They were terrified of me, blood worms, flake food, light, darkness, gravel, plants, snails and existence, in general. I decided to reassess in the morning and possibly employ the dither fish strategy I saw in the recent Coop video.
My little grocery store angelfish had not improved by morning and still would not eat the very scary, high quality food stuffs I tried to feed. Enter: the molly fry gang. I added four 1/2 inch black molly fry--too big to be eaten. They have all the confidence and general boisterousness of their adult counterparts on a much smaller scale. It worked. Within a few hours the angelfish were moving with confidence in the tank, even when I approached. When I threw some Fluval Bug Bites in the tank they greeted the food with the kind of piranha-like enthusiasm I've come to expect from angels. Now they have taken up the angelfish hobby of repeatedly testing all flotsam to see if it's edible.
If I were a better photographer I could show you how beautiful my new angels are. It's truly a test of will not to go back and buy up the lot.