sump design

[Fishward]

personally, i would reduce the area you have set aside for rock and increase your return area. unless you have an ATO, you'll want that area to be as big as possible to reduce the frequency you'll have to top up fresh water. that is the area you'll notice all your evap.

Some people like to have their LR refuge before the skimmer to eliminate all the large particles. leaves less chance your skimmer pump will get plugged with gunk.

I personally drain my tank into my DSB/refuge, over short baffle, just to hold the rock in, and on to the skimmer. through a bubble trap to my return area where im also planning on putting my media reactors when i get em. Carbon and Phosban.

Lastly, before you set your baffle heights, make sure that the difference between your operating depth of water and the rim of your sump is enough to handle the draining of your tank in case your pump stops.