Hi, I had a visi-jet skimmer in my frist 30 gal. set-up. I bought it new and I could'nt get it to skim anything. So finally I called the guys who made it, they told me to set the flow rate at 50. I did that thinking it wasn't going to work but the next day maybe even longer it started working. After I had that bit of info it worked really well, except it did take up a whole corner, and it's held together with plastic zip ties. Buy alot of these, because when you take the skimmer apart to clean it. You will want to use new ones to get a good seal again. The old ones will hold it together but sloppy!