Nice thinking. BTW, hostility was not intended. The other comments were not directed at you. There are inconsiderate jack holes that troll the DIY section looking to start some conflict. Of all things, one of them even has no demonstratable talents but persists coming to the DIY board and trying to stir "it" up.
Also creative thinking will get you farther in life than anything else. (Except maybe sleeping with the bosses wife.of course that could get you a new job too.)
To develop your design further, think of what could go wrong (from the simplest to the worse case scenario.) What could you do to prevent the problems that could occur. (hint: how could you prevent an overflow, what could happen during a power outage.) Also what could be done to make it even more automatic (anything to removing the human element).
THIS IS NOT A KRITIZIZM...
With the drip system and your system how do you treat the water for chlorine (etc,) before it gets to the fish. ( seriuos part of question )
You could use a syphon system but regulating that would be crazy. Metering pump hooked to a float switch so when water valve opens, it turns on for a preset time (oh yea need a timer) ... hhmmm... Rube Goldberg comes to mind ..atleast if I'm building it he would.

of course that could get you a new job too.)
