I dont mean this mean but you have to find them cichlids a new home! You could probably go with 3-5 of them, just depending on size in your 20. Right now you are way overstocked! Remember to research! In the 55 i would say you could get 6-10 just depending on the size, filtration, and setup. Them fish arer going to grow, most at least 5''. That is 75'' of fish in a 20. I could see 15 neon tetras though in the 20.