I couldn't live with the micro bubbles mine put out so I bought the box. It solved the bubble issue but I don't think the skimmer worked as well. I know they claim it works better but the pump just wasn't strong enough to suck water from the surface, IMO. The water in the prefilter box was stagnant even with a Mag 5 pump instead of the Mag 3. The sponge in the bottom of the prefilter box had to be constantly cleaned or it would cause the return to spill over the top and cause micro-bubbles again. I have since taken the box off. So, I would say try it without and hope the bubble issue is not an issue for you.