A 55 will not solve the angel problem. You should remove the extra male to solve the problem. Angels pair and they do not tolerate interlopers. TThey often will protect their space and their eggs against other tank inhabitants going as far as killing some of them. It is important to understand that fish eggs and fish fry are seen as food by many fish, sometimes this includes the parents.
When almost any cichlid, even the seemingly peaceful ones, become very aggressive and nasty when in spawning mode.
Be careful messing with peroxide it tanks, it can kill fish, I have seen it happen.
Plants need light to thrive. Sunlight is uncontrolled in terms of a tank, especially in relation to what comes through windows. As the seasons changes the position and angles change so you may not get much light at some times of the year. get a light for the tank. There are a ton of low light plants one can get which will thrive in a lower light tank and which will need minimal care.
Here is an excellent plant site I have used their fertilizers now for almost 15 years http://tropica.com/en
They have a wealth of information on plants and their needs and they have how tos, including vids, of everything you need to know to have a successful planted tank.