prizms work fine for smaller tanks, but IMO, they are way over-rated on size, skimmers although expensive, are the one item that you definitely get what you pay for and you want a good one, if you can afford it, i would get a better skimmer, do you have a sump??, if so and you don't need a hang on, look into building your own, there is lots of info out there on building one and much cheaper than 200$, but if you are limeited to a hang on, this may not be an option 4u
HTH