First time sump question.

[chopsteeks]

For a pump that's $200+ I'm hoping it's accurate. What size should I get then. Next size up is ether 900 or 1000 which wouldn't that be draining too much for my pump?

The rate of the water flow is determined by the gph of the pump so, no it will not drain any faster than your pump can return back to the tank.

It it is safer to have a larger/bigger If your pump returns the water faster than the overflow can drain, your water will be all over the floor.

 

[MilitantPotato]

Here's a video.
He's using a dosing pump, I prefer the powerhead placed in the sump.