As long as you keep the pond isn't exposed to too much direct sunlight and the fish are decent sized the temperature change shouldn't matter that much. How many gallons to you think it will be? The more water, the harder it is to change the temperature.
__________________ 29 G FW Planted
Anubias, Java Moss, Java Fern, Acoras, Aponogeton Ulvaceous
Neons, Siamese Algae Eating Sharks, Dojos, upside down cats, serpae tetras, Clown Loaches, Ghost Shrimp, Flower Shrimp, and 2 African Dwarf Frogs |