MJ's are good. You can modify them (www.mjmods.com) and make a MJ1200 comprable to a Tunze6060 (2000gph). I'm going to try this for my new tank. You can do a closed loop without drilling your tank if you want. Just have two tubes say 1" going into your tank, cap the bottom off and drill a few dozen intake holes all the way around it... have both pipes go over the back of your tank and merge into a 2" hole and you can get a very large pump like a sequence and then have it pump back up into your tank. Looks pretty good too, it's an alternative to drilling your tank.
