I have a tree house in my backyard and I would like to know what kind of materials and plants i would need to use to start an outdoor fish tank. The area does not get too much sun and i heard that anacharis plants provide oxygen given that i do not have a power supply available up there, which means that i can not control the heating and oxygen flow. I heard that fresh water fish are best for outdoors because they have a high temperature tolerance. What kind of fish would be best for this weather? Is there any possible way for me to keep them happy and healthy in the Canadian summer weather?