ever had any issues with it avionics?
well for a 300g tank I'd like to more water on hand than 55 gals.
toejam the only thing i'd be worried about is lack of movement in the water. I read somewhere...cant remember where atm, that you should keep the water moving a bit to keep it from going stagnant. I planned on mounting a small water pump on a timer in the big one just to keep it stired up.