If you ever have seen my tank befor and after skimmer was installed. You'll be surprised!!! It does a lot more then you think. My tank was very cloudy before and couldn't understand why since I keep up with water changes and all. Ever since I installed the skimmer, the water is clear as ever. If you keep your fish well fed, a skimmer is a absolute to remove excess protein waste from your water cloumn. I don't keep a skimmer on one of my tank, it's doing fine but it could do a lot better with a skimmer installed. Which I will install one once we upgrade the tank sometime soon. Once you get one installed, look into the collection cup once it starts working, you'll see what it pulls out of your water. You'd be surprised!!! :happyfish