Finish the following sentence with the best choice: How to purify your water manually?

Choices:
- For water purification, carry a Katadin water purifier without spare filter element and Potable Aqua water purification tablets. They can purify up to 500 liters of water each,
- For water purification, carry a Katadin water purifier with spare filter element and Potable Aqua water purification tablets. They can purify up to 500 liters of water each,

Answer:
For water purification, carry a Katadin water purifier with spare filter element and Potable Aqua water purification tablets. They can purify up to 500 liters of water each,