Ok, so I won't own a tank that isn't drilled... Just my preference. I'd drill it.
But... you don't _need_ a sump. Really, in today's world, a sump is simply a place to hide all the stuff you don't want in the display. I can't think of anything, really, that you can't do as a hang on, or in-tank version, rather than a sump version.
My sump contains some live rock rubble, macro algae refugeum, heater, kalk dosing outlet, temp and pH probes, ATO system, and return pump. Nothing that can't be done in the tank, or as a hang on, or just eliminated.
But... you don't _need_ a sump. Really, in today's world, a sump is simply a place to hide all the stuff you don't want in the display. I can't think of anything, really, that you can't do as a hang on, or in-tank version, rather than a sump version.
My sump contains some live rock rubble, macro algae refugeum, heater, kalk dosing outlet, temp and pH probes, ATO system, and return pump. Nothing that can't be done in the tank, or as a hang on, or just eliminated.