Asylumdown's 275 Tank build

[asylumdown]

The water in the return chamber should (hopefully) never fall below 7 inches. In order to be able to do the largest water changes possible, I had to increase the depth of the water in the sump to 17 inches. It will mean the skimmer needs to sit on about an 8 inch stand, but I have a custom height aquarium stand and the Deltec's are 23.62 inches tall (it's why I chose them), so I still have plenty of clearance between the bottom of the aquarium and the top of the skimmer. That will mean that the baffle between the fuge and the return channel will always be under about 10 inches of water. I only created that baffle so that water entering the fuge/return channel from the water change chamber wouldn't be blasting at it's highest velocity over sand & algae, and to hold the sand up from falling in to the return line. If that's the case, do I even need a bubble trap?

If I had no bubble trap, I have 2 options:

1.Put an 18.5 inch baffle right after the skimmer so that the water level in the skimmer/input chamber would be a constant 18.5 inches. I still have plenty of clearance between the top of the skimmer and the bottom of the tank if I make the stand the skimmer sits on 9.5 inches high. Then the water would pour into another chamber created by the space between the 18.5 inch baffle and the centre baffle. During normal operation, the water height in the rest of the sump would be 17 inches, but when I isolate the water change chamber to do a water would, the water in the chamber after the skimmer would rise until it poured in to the fuge. This design would have some water tumbling during normal operation, but it would be tumbling several feet (if the water path was a straight line) before the return pump.

2. Not have any height setting baffles at all. The water height in the entire skimmer would be 17 inches, and the entire sump level would fluctuate with evaporation. When I close the gate valve between the sump chamber and the water change chamber, the water will rise an inch to an inch and a half before it pours over in to the refugium chamber. There's going to be an auto-top off system, so this might be feasible.

Any thoughts?

Also, would making that channel from the water change chamber to the return pump 4 inches wide be enough for a 1 inch return line?, that would leave 1 inch on either side and a 2 inch hole.