Currently in my tank right now i have 7-9 platy (some of them are fry so im not sure) and am wanting to add new fish sometime next week. I want to add 1 angelfish(if they can be alone), 2 dwarf gouramis, and potentially 1 albino cory cat (if they can be alone). Would this group of fish live peacfully together, or will some have problems? If so, what are some suggestions that could fit well in my tank. Also would this mix of fish cause my 30 gallon tank to become overcrowded? Thank you in advance!