Please use the provided funnel/wrench tool to remove the cap and to act as a funnel for easy pouring and water removal.
Do not use a substitute tool, damages may occur. Do not fill the pillow with anything other than water.
The amount of water you add, really depends upon how soft or firm you prefer your pillow. We recommend staring with 3 liters / quarts which would be classified as medium. After sleeping on the pillow for a few nights you will know if this is the perfect amount for you, if not we recommend adding or replacing 1 cup of water at a time and testing the pillow while you sleep.
Soft = 2 Liters/ Quarts
Medium = 3 Liters/ Quarts
Firm = 4-5 Liters/ Quarts
Detailed Instructions can be found on the inside packaging of your product.