Boston beans are baby boxfish.
You have a bunch of options for very small tanks. Nitrate problems can likely be minimised by doing weekly or twice weekly water changes (if changing a gallon twice a week is to much for people, then they have little chance of doing well with a nano). I actually quite like the idea of using a can with a spray bar return for filtration + water movement, and using live rock in the tank. This way you could get away with less live rock chewing all the space, and just aqauscape to the fishes comfort. You could also use an inflow heater on the return pipe and not have the heater in the tank. Something like a small Eheim Ecco would be good on a 10.
Alternatively I think the combined heater/powerhead or heater/filters would be a good call.
You have a bunch of options for very small tanks. Nitrate problems can likely be minimised by doing weekly or twice weekly water changes (if changing a gallon twice a week is to much for people, then they have little chance of doing well with a nano). I actually quite like the idea of using a can with a spray bar return for filtration + water movement, and using live rock in the tank. This way you could get away with less live rock chewing all the space, and just aqauscape to the fishes comfort. You could also use an inflow heater on the return pipe and not have the heater in the tank. Something like a small Eheim Ecco would be good on a 10.
Alternatively I think the combined heater/powerhead or heater/filters would be a good call.