Help with my prizm skimmer

HI I have decided to hook up one of my old HOB prizm skimmers to my 20 gallon reef since i'm having a battle against nitrates right now and the water changes are helping but I am hoping the skimmer will help even more. Im not sure what model it is but it is rated for up to 100 gallon aquariums. Its been about 2 years since I've run this skimmer and I don't really remember how to use it properly. On top of it I can not find the original boxing which had instructions. Im pretty sure I have it assembled right. Does anyone have any experience with these types of skimmers? If pictures are needed I can provide them. Thanks!!!