Jar ingredients question?? (I wasn’t sure what to title this)

So I am making a Jar based around helping me study but bc I have some organic matter in water I’m worried about potential mold

The idea is the Jar is a shaker jar and I shake it a little to activate it so I wanted water into the jar to make the shaking a little more subtle for when I’m around others.

If anyone has any ideas on what I could do