Only use Gatorade or G2 bottles for the sensory bottles they are a heavier plastic so they hold up better and keep a unison look so everything looks good. They come in different sizes you can find smaller ones for small hands if you need to.
Make sure to ALWAYS seal your bottles securely! I cannot emphasize this enough. Unless you want your bottle opened and the contents poured out. SEAL IT… with glue. Duct tape can be peeled off by a determined kiddo. Glue is much harder for them to open up.
Wet vs Dry Discovery Bottles
Make sets of bottles filled with different things like dried beans, curling ribbon, glitter, glass beads and tissue paper. In one bottle from each set add water in addition to the beans ribbon, glitter, glass beads and tissue paper. Observe what happened inside each bottle and record observations over a few days time. Watch the bean bottles and the tissue paper bottles. Listen to the difference in sound in each of the bottles.
For a list of ALL my amazing DISCOVERY BOTTLE IDEAS click the link or the image below