Despite being made to function on windows up to 3/4" thick when feeding normal-sized fish, our VeggieMag's magnetic coupling can be disrupted by large angelfish, Naso tangs, triggerfish, or harlequin wrasse, among other voracious, powerful creatures. Even running at it and ripping it off the wall gives them enormous joy. The MegaVeggieMag, which uses a 1" diameter x 1" long ultra high strength Neodymium magnet will maintain the clip's position. Observe the amazement in your large fishes' eyes as they attempt to remove the clip but fail. Make sure to fold the SeaVeggies sheet into a thick layer that will fit inside the jaws of the clip.