Full Christmas trees look great, but they can be a pain when it comes to watering them.
If your tree has low-hanging branches it can be difficult to see whether or not you need to fill the tree's water. Reddit user SolidDoctor has an easy solution to the problem: Put a ping pong ball in the water reservoir.
When you can see the ball, it's floating so you know your tree has enough water. If you can't see the ball, then you know you need to give it water. Add water until you can see the ball again, and your tree won't be thirsty.