I know which pump they recommend but was wandering if they are other pumps you guys use for this skimmer or if any one has a used BL-55 for sale?<span style="color: #000000;"></span>
A mag 12 will not work at all. These skimmers require a pressure rated pump in order to work well. If you don't have pressure, you can overcome it with flow.
So, a dart will work for the MR-3. You may have to throttle it back a bit if you're only pushing one injector. The darts are very energy efficient pumps; a good alternative.