anyone see a problem with this idea?

My personal opinion would be that currently you have too much flow throw you filter. I think that if you T'ed off the return and split it between the skimmer and main tank it would be alot better. The MR-1 only calls for 1200gph and I believe that 1800gph to the main tank would be good. I don't even have that much on my 180g. I would do it.

 

dzabler has an MRC MR-1 and he runs a Mag 18 on it with great results. I would recommend checking with him to see if he has any recommendations. The 120 has dual overflows rated for 600 GPH each, right? Seems to me that by the time you split it between the return and the sump, you should be fine. My concern would be using the return pump for the skimmer. Will you be having the skimmer dump directly into the tank? If not, then you could just be skimming the same water over and over again. I guess that's kind of the same concept as a recirculating skimmer...maybe it would be fine...I don't know. Add a t-on your plumbing and run your other stuff off it too like your reactors, maybe a frag tank...seems like that pump is sized just about right.

--AJ