Kev Porter shows how to purify water using tablets. Kev advises that the first thing to do is read the instructions on the back. He uses portable water tablets. You add two tablets to a quart or liter of water. Place the cap loosely on the water bottle, wait five minutes and shake it. After shaking, you have to wait another three minutes making sure you tighten the cap. Once three minutes pass, add the neutralizing tablets. Place cap back on the water bottle tightly and shake it. This takes three to five minutes. No need to wait for the tablets to dissolve. You're now ready to enjoy your water.