Hi i have a 30 gal with 3 male guppies, 4 mollies (2 female, 2 male). I also have 5 Two week old mollie babies in a nursery tank inside the 30 gal. I also have 1 peppered cory cat. I am wanting to add a bn pleco for algae. Can i also add more cories so my 1 cory can have some of his own kind? How many cories could i add if i add a bn pleco? Also how many do i need to add at a time so i wont burden the bacteria colony? My tank is established, just want to keep it that way! Thanks all!