Two Little Fishies VeggieMag is a powerful magnetically coupled clip and feeding point for holding seaweed or other food items on aquarium walls. It can be easily positioned at any level and removed from the aquarium without getting one's hands wet.
The clip assembly floats if it becomes uncoupled, and the outer magnet has a special grip-and-release polymer that holds it on the wall if the clip becomes uncoupled. Safe for glass and acrylic, but one must prevent picking up sand or gravel that would scratch the aquarium surface.