People are crazy about water walking ball game, but it would be unsafe if you play it without following the following advice. Player can stay inside the ball for 10-20 minutes top to enjoy the fresh air. After that, they should get outside the human size hamster ball and get the fresh air refill before going inside and playing again. The steps of refilling air are pretty simple. You need to open up the air intake valve and insert the air blower and there you go. It is also okay to stay inside while refilling air if player refuse to go through the trouble. And we should not play water ball alone, there should be at least two people to keep each other alarm to remember the air refilling time. There must be parents around while children playing water walking ball.