I have had a tropical tank for years but I am no expert, I have kept Discus for years but sadly the last of them died about a year or so ago so I decided to give angel fish a try, I bought 4 angel fish about 9 months ago and are already 3 times bigger, I have one of them that is a bully but I would really like to add something else I have tried gouramys platys, swords but they lasted 3 hrs before the angel fish killed them I even have a large sail fin plec with them and they nip big holes in his large fin. The 4 angel fish look lovely but boy are they aggressive. Can I introduse a few new angel fish or would that be a disaster. My tank is a good size 4ft x 2ft and has plants and wood in but it would be nice to see a few more fish in it.