I have a 15gallon aquarium brought last April with 7 carp, 1 japanese koi, 1 shubunkin, 2 silver tin foil and 1 small tuna. with artificial plants pebbles and undergravel filter with two(2) air pumps. I will sell it for only 2, 500 including the fish, air pump, undergravel filter and the tank. if yo...