Recognise this guy? He is the one to make your water ultrapure by removing impurities and contaminants from the tap water!
And he's doing a great job; the water that comes out of him can be used for super sensitive things like mass spectrometry and DNA sequencing.
Buuut.. he is also using a lot of energy and a lot of WATER to produce that ultrapure water.
In fact, some water purification systems send 80% (!) of the input water directly down the drain.
So every time you are about to get some water, ask yourself:
What kind of water do I need for this? Tap water? Deionised water? Or ultrapure water?
A higher purity of water comes with a larger ecological footprint.
So don´t use ultrapure water just because you can -- use the right water!
And remember to treat your water purification system well to prolong it´s lifetime.