*help with against gravity dual-drain design please*


Reefing newb
i'm learning the 50g isn't going to cut it as a frag tank as it's nearly full and i've just begun. so, i'm adding an 80 rimless just outside the fish room as a show frag tank.

on a separate project i'm making my skimmer external and placing it against the far wall in the fish room for easier maintenance and to create room in the sump. the skimmer is inside the fish room behind the wall that the new 80 frag tank will be outside the fish room.

problem is that the entry door to my fish room is between where the new frag tank will be and the sump to the existing system.

the easiest way to plumb the new frag tank in is to go straight down to the floor (30"), through the wall, across the fish room floor (12'), then up the sump exterior (18") and into the filter sock chamber of the sump. so i got roughly 10-12" delta between the drop and rise. the skimmer is inside the fish room and the drain at approximately at the same height as the tank that is on the outside of that wall. i'd like to be able to have both of these drains (the skimmer's and the new frag tank's) drain into one pipe across the fish room floor and back into the sump to keep things more clean looking and simple.

the skimmer will be fed approximately 500-1000gph. the frag tank can be fed whatever gph it needs to to make this work with the appropriate plumbing size but likely around 500gph as most the circulation will be from power heads for the SPS frag tank.

pipe along the floor and entry-way isn't a problem as that is easily concealed and protected.

so...anyone familiar with how i can successfully get this done? is it possible? what size pipe should i use for the drains and main drain back to the sump? what kind of flow would be necessary to combat the gravity? anything else i am missing or not thinking of?

here's a rough sketch i put together to put a visual to it. sorry, i don't have sketchup on this computer but i did try to keep things to accurate scale.


thanks for any help you can provide!