Here is my idea:
It’s always hard to keep up proper hydration levels (consider athletes and people trying to lose weights), so I thought of a water bottle system that would react according to the amount of water that is consumed throughout the day. It would remind you to drink water with a set of pulsating color LEDs if you haven’t kept up with it and would reward you with a nice green glow if you achieved the target quantity by the end of the day:
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