So i need advice on the type of skimmer to put in a sump on my newly aquired 75gal. It has a 29gal sump. I see some rather expensive ones then i see this and wonder why this seems to good to be true http://www.drsfostersmith.com/product/prod_display.cfm?c=3578+4392+13924&pcatid=13924 .......its not that im trying to be cheap, but i need to understand what i should be looking for in a skimmer. So that being said i want value in what i buy i dont need the best but i dontt want to be super cheap also.