but cant afford it the lfs told me
Unfortunately, a skimmer isn't something you want to skimp on. A skimmer is one of the most, if not most, important part of your system. Start saving and buy a good one once. Many of us didn't have the money at first and bought a cheaper skimmer, but only to find out that it was in-efficient or broke down as pearson74 experienced. Stay away from a Prizm, they are cheap, but perform that way also.
Just do a few more water changes than normal, and wait until you can afford a good one.
how big is your tank?