help setting up protein skimmer

its driving me nuts ! , little info on my system.
230 gallon dt.
80 gallon sump.
reeflo dart (older model) all metal
areofoamer 800 series. (older model)

for weeks now ive been trying to set up my skimmer. and just can't seem to figure out why water is leaking out of the venturi valve tube and the water rises over the venturi chamber and leaks underneath the lid. if anyone has this skimmer and knows how to set it up please help me . I'm about to throw it out the window!!

this skimmer isnt in the sump. its outside it , beside the tank. its not a hangon tho .

no the pump isnt in the sump and yes its the right size its the reeflo dart