I have a 75 gallon tank with 6 angelfish in it as well as 5 black skirt tetras and a cory cat in it. Idont like bright flashy colors more the blacks brown and natural looks. Id love to add another school of somethings that arent fin nippers and will go well with this combo. I have a emperor 400 with fluval heater and plenty of aeration. Lots ofdriftwoods and plants. Any suggestions? Also how many more fish would i be comfortable with