I absolutely love my AquaC EV spray injection skimmer. It is external, which means it doesn't have to be in sump. Mine sat right behind my sump and drained into it and was run by a pump in the pump section of my sump. This saved room in the sump for more refugium. You have control over the flow in, air in, and flow out so you can tweak it to get exactly what you need. It also has a drain in the collection cup to hook to a larger skimmate collection container (yours or they will sell you one). Large reaction chamber means it's very effective.