other things to consider. if you have a mag laying around, why not use it? I have not found it a problem to run in sump pumps heat wise either. I am using a 55g tank (tempered on all sides) as a sump so I am not likely to try and drill it for bulkheads and run an external pump. everything I have is inside the sump so if a connection leaks a bit I dont have to worry about it. the skimmer is rated for over 200g (i think) so running it on a 125 with a less than ideal pump is not a performance issue. foams fine. believe it or not this is not a right or wrong way of doing things. no two set ups are the same. some people pour all sorts of additives in their tank, others use none. either one or both can have fine looking corals. more than one way to do things. in the future if this skimmer is moved to a larger tank and I need max ability from the skimmer, then I will step up to a pressure rated pump. but for my simple needs, I can still say it works. Thats even pushing through a couple of un needed elbows that the skimmer came with. eliminating those would be a helpful also but for now all is well. perhaps the thread starter could barrow a mag and try things out as he makes his decision.