I purchased a Prism skimmer as i am on a budget right now. i brought it home, plugged it in, and it seemed to be working fine. it was skimming with minimal flow. now i have to have the flow opened all the way or else nothing and very minimal stuff coming out. I've had it for a week and i don't know what to do. should i bring it back. i tried that and the guy plugged it in and said that it's okay they will not give refunds and i want to know if this is common for a prism hang on skimmer. any suggestions please