What is the cup of water under the bed mean for santeria religion?

Okay i know a little bit about Santeria because i had people in my family into this religion but i heard for protection i should put a cup under my bed with water? Is that true? Is it for protection? And when should i change it? Can i put Florida water instead?

nothing....go to the faucet and use a glass

Chamber pot?

Holy water.. seriously? You have to ask?

In Vodou it's a protective charm, which is normal water (sometimes salt) poured with a prayer to Yemonja.

Don't drink it! It's pee!