Affix nori to feed your tank with a reliable clip that is held to the wall of your aquarium magnetically! I've been using these for my tangs for several years.

The VeggieMag uses magnetic attraction instead of a suction cup to hold our SeaVeggies clip in place for windows up to 3/4” thick! It’s easy to position at any level in the aquarium, and easy to retrieve it without getting your hands wet. As an added feature the VeggieMag floats! Patent pending design by Julian Sprung.

Melev's Note: I love the ability to slide the magnet upward to the top of the tank to remove the inner half when reloading it with sheet algae (nori). If the two halves become separated, I've seen the inside half float around as the fish chase the food, but the outer half will stick to the glass -- no doubt because I keep the glass so clean.  If it does fall off and you have a steel stand, odds are you'll hear it snap to the metal below.  It's a great product; before this existed I had some magnets dipped in plastic and secured a clip to it.  This is a much better looking product and will last for a long time.