- Wash and rinse the bottle and lid.
- Fill the bottle 3/4 full with vegetable oil.
- Add water to fill the bottle the rest of the way, stopping 1/4 inch from the top.
- Add 8 to 10 drops of food coloring to your chosen one.
- Break the antacid tablet in at least 8 pieces. The pieces fall into the bottle, one at a time, allowing each one’s effervescence to go off before adding the next.
- Screw the lid on the top of the bottle.
- Place a flashlight under the bottle in a dark room and enjoy the show.
Tips and warnings
- If you have a lightbox, replace it with the flashlight to have your hands free.
- You can substitute salt for the antacid tablet by adding salt until the contents of the bottle begin to bubble and move. Add more salt as needed to keep the process active.
- Protect work surfaces against spilled oil and food coloring, covering with paper or plastic.
- When making a lava lamp with children, use a plastic bottle to avoid accidents with broken glass.