If you've got too many water beads on your hands then follow our tips to dispose of them in a responsible manner:
The most important thing you should NOT DO is put them down the drain. If you do this then they will be taken out into the environment (and possibly even out to sea where they'll be mistaken for food by fish).
Instead, it's best to dry the beads out for use at a later date. Simply lay them out on a tray and wait. They will slowly release moisture and shrink in size until they reach their original form, at which point you can put them back into storage or give them away for others to enjoy. If you need to hurry them along a bit then lay them out in sunlight.
If you're not interested in drying the water beads out then you can mix them into the soil in your garden. They will absorb and release water for 1 - 3 years before breaking down (which is actually another one of their uses as this helps to prevent soil from drying out so quickly).
Finally, if that doesn't suit you then it is best to put them into the trash. They'll end up in a landfill somewhere (which is a shame!) but due to the desiccating nature of landfills the water beads will shrink down to almost nothing and only take up a few centimetres of space.