Instead of buying expensive pool LEDs from the store, you can make one in 15 minutes with a few materials. This is guaranteed to work, and is very simple to make.
Step 1: Gather The Materials
You will need a few materials to make this project.
1 small clear plastic bottle with the lid
1 battery pack from a old flashlight
Glad Press-n-Seal wrap (or opaque Cling- Wrap)