I use a skimmer. I actually just spent $1000 to make room for an ATS and installed an external skimmer. I'm not trying to convince anyone. I'm just stating that it's not necessary. It's not necessary to wear clothes in my house, but I do.JMO but your wasting your time trying to convince the folks that worship skimmers that they aren't necessary. I swear some of them act like they are in a cult and the skimmer is God and life in our tanks can not survive without one. Had a member the other day say that not running a skimmer was like having my fish living in a septic tank. Gotta love the internet