You can make your own lava lamp with items you have around the house!
You will need:
1. Add water to your bottle
2. Color your water the color you would like with the food coloring.
3. Add Vegetable Oil (Pour it down the sides to keep it from mixing – It will separate over time if they mix )
4. Add Alka Seltzer
5. To make it a little more interesting and see the effect you can add a balloon to the top of the bottle. The balloon will inflate as the gas is created from the water and alka seltzer and will collect in the balloon.