My tank is only big for the room it is in so I have to work overtime to make it MONSTER 120 GALLON ......5" Mata Mata Turtle and South American stock. 2x 24K kelberi ( thought they stayed 12" oh well.....) Two gorgeous Lenticulata Pikes, 3 spotted and two thin Barred SD, 1x Vampire Pleco ( not seen in three weeks.....in the caves!) One adult Sydont Squeeker cat, one Golden and one marble Angel. The rock pile allows the turtle to walk up the the surface.....for a fully aquatic species Mata are horrible swimmers. My PH is 6. So far no damage to any fins....still trying to pellet train the Kels and Pikes