I use a skimmer with dsb and refugium. I will alway use a skimmer. I had skimmerless tanks also. DSB isn't good at getting rid of organics more for nitrogencycle
I went skimmerless for the first two years in the hobby and wished I didn't. What a difference it makes in water quality. I have a CPR bakpak with a Filstar cannister and a DSB .