That's marinedepot.com saying that, not Danner.
I can't find much on the Danner site, but it does say submerged or inline.
I wonder what marinedepot has against using them inline?
Too many returns from people installing them wrong for inline use and trying to run them dry?
just got my new mag drive 24 for my 180 gal tank that i'm setting up. as stated by the manufacturer you can either do a submersible or inline (outside the sump).
