Yes, you cannot use the pre-filter attachment on the mag 3 ( we use a Maxijet, and there is no way the pre-filter would fit in the pre-filter box) anyway, you are also right about the way the box is attached to the skimmer, there are two screws sticking out of the pre-filter box which you are supposed to tighten to attach to the pump... what I did which I thought was rather ingenious (AHEM) was I used the suction attachment that came with my maxijet. Now my pre-filter has suctions on the back and is not attached to the glass with the suctions. This makes it easier to lower or raise the pre-filter box when the water level gets lower due to evaporation or during top-offs, respectively... I love my aquaC, good luck with yours.
65 Gal Marine
60lbs of LS
and 100lbs of LR
EHEIM 2215 Canister Filter, AquaC Remora Protein Skimmer w preskim box, 36" PFO Lights with 2x 250W 10K MH
and 2x96W T3 Actinics, JBJ Arctica Chiller 1/10 hp w/ Eheim 1250 Pump, Turbo-Twist 3x UV
Sterilizer 9W, (1) Yellow Tang
(1)Potter's Angel, (2) Skunk Cleaner Shrimps,(1) Eibli's Angel, (26) Turbo Snails,(10) Nassarius Snails, (2) Sand sifting starfish
(1) Regal "hippo" Tang, (20) Hermit Crabs, (1) Coral Beauty, (1) Pygmy Angel, (1) Serpent Star, (1) Brittle Star, Pumping Xenia, Finger Leather, Yellow Polyps, Green Star Polyps, Colt Leather, Mushrooms, (2) Maxijet 600 PH
and (2) Maxijet 1200 PH
Am I Overstocked Yet?