I'm working on the 20g rimless now. It was either the one you picked, a remora or a tunze. I;m still waiting for a good deal on ebay or locally but I;d love to now how much it pulls out of your water.
In my 55g which is kinda empty my remora still pulls some black liquid, just not very much since theres not anything in it but inverts, which i still feed.
In my 125g the skimmer pulls out some really thick nasty black goo water that literally smells worse than death. Once it breaks in and you get it adjusted it should be pulling out murky goo. BUT it also will only pull orgaincs from your tank so if you dont have much it won't seem to be working. lol
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.