[tbittner]

I take it that your overflow box can exceed the pumping capacity of the pump? You have a ball valve on the drain but you don't have one on the return from the pump so you can't slow down the pump if you need to.

It also looks like the return pipe is an inch or two above the water. That's going to create a LOT of salt spray. It does prevent a back siphon if the electric goes out but it's going to create a bit of a mess. You'll get salt creep all over the place.