Unless your nutrient levels are extremely high, your collection cup isn't going to fill up that quickly. If the skimmer is properly adjusted, it will produce a dry foam and would probably run a week at a time. You can drill the side of the collection cup, install a small hose barb, and run a drain line down to another container. My suggestion for a 40g tank would be an Aqua C Remora and you can order it with the drain fitting. It's a much better skimmer than the Jebo or Seaclone. You get pretty much what you pay for in skimmers. Any skimmer is better than nothing though as long as you don't buy a Prizm (
IMO).