Found on Juggling with kids website; there are great, simple intructions and videos to show you what to do ...................very easy!
Fill each bottle about 3/4 full of vegetable oil. Fill the rest of the bottle with water...but leave about an inch at the top...or it will overflow. Break your Alka Seltzer into tiny pieces and drop them in one piece at a time.
Thank you Juggling with Kids for this great sensory/ science activity.