[konidias]

Look.. you plant a tree, it shows up as a sprout with the blue bar at around 75%

You water it from then until it says "ok" the meter is not a "water meter" it is a time meter. It has 4 stages.. "ok" blue, red, and red warning.

Each time the tree grows, you must water it constantly until it says ok.. if you don't it will eventually get to the critical level and die.