I've been watching this thread for a bit now. I am in the process of planning whether or not I want internal or external pumps for my new
sump.
I've been very happy with the Mag Pumps I've had. I did have to file down some silly manufacturing "dimples n pimples" near the magnet and impellor drive, but otherwise, they've been great.
I've been more concerned about leaks, and heat transfer. I've been doing some reading myself and as usual, the answer comes down to 'tank specifics'.
If your tank has heat issues or marginal heat issues, or if you have real estate issues in your
sump, then external is the way to go. The chances of leaks or failure seem to be very much like those of internal pumps.
If you don't have heat issues, or problems finding the footprint for an internal pump, then it SEEMS like the way to go. For no other reason but if it does spring a leak, you are still keeping any spillage within the system. The only downfall is if you use pumps that are internally lubricated with oils etc. and that casing cracks. This, according to my "googling" is not all that common.
I'm going to use a Mag 20-something for my return pump and run it internally. I'd like to go lower, but the 'head loss' seems to be a factor for me. I'm pumping water from the basement to the family room on the first floor. Tht is over a 14' rise for me. Therefore, I need some serious pump!
Be well.
Dave
