This is the render for the sump:
Three 1 1/2" inlets with bulkheads
It will be 1/4" glass and the top will be cut using waterjet cnc cutter
The return pumps will be external to the sump
For ATO I will be using this optical sensors:
They will activate the rodi unit booster pump and inlet solenoid valve.
As redundancy it will have a float valve and mechanical float switches wired to the apex as failsafe for low and high sump levels