Assuming you would like tips on filtering water using a 2-liter bottle:
One way to filter water is by using a 2-liter bottle. This is a quick and easy way to filter water when you are in a pinch. All you need is a 2-liter bottle, some cotton balls, and charcoal.
First, take the cotton balls and put them in the bottom of the bottle. Next, add the charcoal on top of the cotton balls. Make sure that the charcoal is evenly distributed. Then, slowly pour water into the bottle until it is full. Let the water sit for about 30 minutes so that the charcoal can filter out impurities.
After 30 minutes have passed, carefully pour the filtered water into another container. Be sure to not pour too quickly or else all of the charcoal will come out with the water. And that's it! You now have filtered water thanks to your 2-liter bottle and some simple materials