Originally Posted by Hinds04
What does the skimmer actually do. I'm doing a 75 gallon reef with a 30 gallon sump and I am dreading buying one.
A skimmer takes proteins and some floating debris out of the tank. Problems that you can get from no skimmer are, foul smelling tank, high levels of nitrates, and cloudy water, to name a few. Harder to make operate with only a sump... you really would want a refuge where you could grow lots of macro algae to help to consume some of the nitrates. Also you may
not be able to have as many fish without one.