If weekly water changes are done and you dont overfeed or overstock you should be fine without a skimmer. I dont run one on my biocube and its been fine. The small cheap ones seem to be just that, cheap.
180g Reef - 60g Rimless Reef -90G FOWLR- 125g Malawi Cichlids- 40b REEF- 34g Fresh Planted-working on- 20L FOWLR- working on
I have a mix of many different saltwater fish amongst my tanks, but I love my Tangs most of all.