Looking To Add To Tank, Any Sugestions?

[Kaitie09]

I have a 55g tank with a 350gph external filter, completely planted, currently stocked with 11 glowlight tetras, 6 rosy barbs, 2 bristlenose plecos, and one angelfish. I'm contemplating adding 1 or 2 more fish, but have no idea what. I have soft water and low ph. 
 
Looking for suggestions, or even if that would overload the tank. I like what I have in there now, but of course, am always wanting to add another one. 

 

[BiggTexx]

Angels are normally considered too aggressive for the glowlight tetras.  Have you noticed any aggression yet?  Do you have any wood for the BN Plecos?

 

[Kaitie09]

None at all, actually prefers them to the barbs, and the tetras really don't school much, so they must feel pretty safe around it. I got the angel as a baby and the tetras were full grown, so maybe that helped. I have 2 large pieces of driftwood in there.