I have a pair of H Reidi in a 9 gallon, although this tank is 14 inches high.
Don't get me wrong, I perform two water changes each week, a 10% and 50% EVERY WEEK to keep things stable. It also helps to have no substrate.
If their fatness and 100+ babies are any indication of their health, I'd say they are just fine.
Oh, I must not forget about the computer controlled temperature device that activates the chiller to keep the tank 73F. And oops, I scrub the LR, replace the Phosguard 2 times each week, replace the fiber-fill, and enrich the food and... well...
Now that I think about it, all I have from the original nano tank is the glass tank ONLY. Lights, filters, pump, feeder, controller, chiller, fan, are all assembled by me. I think I have 14 plugs for this tank on that one GFCI outlet. I even made my own stand so I can see them when I am sitting on the sofa. I suppose they are the substitute for my TV.