Light levels dictate everything else.

Light sets a plant's growth. It determines everything else. It sets how fast of a car we're driving today. Is it a Ferrari, or is it a Ford Pinto?

The more light we have, the more water we can consume, the more CO2 we can turn to oxygen.

Water consumption is driven by the quantity of light available to the plant.

Because light and water go hand-in-hand in consumption during photosynthesis, the more light a plant is exposed to the more water it will need. 

Now, don't run off after seeing this next diagram (this isn't a 7th grade science lesson).

 The photosynthesis diagram simply shows light being absorbed, which kicks off a process that helps the plant grow. But it all begins with LIGHT!

Understanding this should allow you to care better for your plant. Are you wondering how much to water? Consider how much light your space has to provide. 

If it's dark, don't water much. If it's bright, water more! Here's a video on that.