Things You'll Need
- Rock
- Toothpick
- Tank-safe epoxy
Instructions
Attach a plastic toothpick to the rock, sharp side out, using a tank-safe epoxy like Aqua Mend (available at home and garden shops). Do this while the rock is out of the water, and allow the epoxy to dry. Keep in mind that live rock will die if it's out of the water for too long, so don't leave it out any longer than absolutely necessary for the epoxy to dry adequately.
Put the live rock back into the water. Gently slide the base of the sponge onto the toothpick, and push until the base of the sponge is touching the rock. The sponge will grow around the toothpick and onto the rock.
Monitor the sponge. Although it should receive plenty of water circulation for feeding, too much movement may knock the sponge off the toothpick and cause damage.