Nice looking tank and rays! Looks like you have a simple comb outlet at the top, does that run the sump or is it for an external. If sump does it drain all the way down to there if the power goes off, if not how do you stop the syphon?
The spray bar gos to a 3600gph reeflo external pump. My sump has a 3/4" drain in it for my 24/7 drip so in the event of a power outage I just get a free partial water change .
Just recently bumped my drip up to 3gph seems to be just about perfect.
This should better explain why it doesn't drain that far down