Whats an E tank?
Blue Mandarin (Ocean Nutrition pellet eater)
Thats your list of fish for the 75. Its a semi light load so you should be OK for a short period of time before the fish start to suffer from O2
deprevation. As devlish mentioned a battery powered air pump is going to be a life saver for this kind of thing. Its not the air that the pump is putting in the water its the resulting water movement that helps oxygenate the water via gas exchange at the surface. If you dont have an airpump that runs on batteries you might have access to a DC
converter like those that you use in boats or trucks to run friges, etc off of your car battery. If you have access to one of those and a spair charged car battery (a deep cycle boat battery is best) than you can hook that up and run some small powerheads to move the water while the main power is off.
The temps should be OK as the rain will result in some cooler outside temps vs the high 80-90 tems we experenced last week. wrapping the tank in blankets (just dont drape them over the top) will also help keep the water temp more stable during this outage.