Two tea tabs

In the breakfast restaurant they have this tea machine. Every morning you could see peoples faces when drinking their tea, they didn't like it.. The tea is too black, you can't even tell the difference between the tea and the coffee. Except when you put milk in your coffee :)

Then a few days ago someone told that you should put water with your tea because otherwise is way too strong. Then people understood were the second tab on the machine was for, you could mix water with your tea.

The funny thing is, people didn't used the second tab before.. The tea machine had two tabs without describing which is which. At first hand you would think it is bad to not put text/icon above the tabs because people wouldn't know which one is tea and which one is water. But it is creating another problem too, people don't even know the two tabs have different function, they probably guess that tea will come out from both tabs.

Btw, we got some nice feedback on our concept today.