How full can I fill my Gravity Water System?

Edited

As a general rule, you can fill your Gravity Water System with two fills of the upper tank. This volume of water comfortably fits into the lower tank without the risk of overflowing.

As a guide, once the water line reaches the top of the lower tank where it meets the white middle ring, the unit is full.

Please note: do not fill the upper tank when the lower tank is full as this will cause overflowing.