I usually keep both tanks around 78 to help prevent certain illnesses. My big tank has 3 fully grown Kissing Gouramis(6 inches each), 2 sun catfish(6 inches each), 2 Striped Angelfish(6-7 inches each), 2 Koi Angelfish(3 inches each), 1 Dwarf Cory, 1 Golden Gourami(4 inches), 1 5-inch Bala shark...