if I understand your diagream correctly (shouldn't the arrow on the far right side/section be pointing upwards as the sump return?), then your sump proper is waaaaay too small for safe running here.
Even with a very precise evaporation top-off system... you will be cutting this close. Without auto-evap top off, you will be a slave to evap and likely burn out some pumps!
As for the baffle on the left side from the first (skimmer?) chamber... it really is not needed if your flow is appropriately slow enough through this sump (it cannot be too high for noice and microbubble concerns... leave the bulk of the flow needs/duty up top on a closed loop or in display pumps).
I do think you would be better served with a submerged refugium spillway/lip at least to get the rolling water flow pattern we have talked about in this thread (assuming you'll keep the typical macroalgae species).
Incorporating a refugium into a sump in such downstream applications (as opposed to my preferred upstream - above sump or next to/above display) is one of their greatest limitations.
And... welcome to the forum, my friend
Thanks for peeking in
