7 Effective Ways to Filter and Purify Rainwater

7 Effective Ways to Filter and Purify Rainwater

7 Ways to Filter and Purify Rainwater


Rainwater is a valuable resource in a survival situation. It can provide us with a source of clean drinking water when other sources are unavailable or contaminated. However, it is important to remember that rainwater is not always safe to drink straight from the sky. It can contain impurities and contaminants that can make us sick if consumed without proper filtration and purification.

In this article, we will explore seven effective ways to filter and purify rainwater, ensuring that it is safe to drink.

1. Boiling

Boiling water is one of the oldest and most reliable methods of purifying water. By bringing the water to a rolling boil for at least one minute (or three minutes at high altitudes), you can kill or inactivate most forms of bacteria, viruses, and parasites.

Here’s how to do it:

  • Collect rainwater in a clean container.
  • Transfer the water to a pot and bring it to a rolling boil.
  • Let the water boil for at least one minute.
  • Allow the water to cool before drinking.

2. Using a Water Filter

A water filter is an excellent investment for anyone who anticipates the need to filter large amounts of water. There are various types of water filters available, ranging from portable ones that can fit in a backpack to larger gravity-fed filters suitable for extended stays or group use.

When choosing a water filter, look for one that is specifically designed to remove bacteria, viruses, and parasites. Some filters also have activated carbon elements to remove odors and improve taste.

How to Use a Water Filter

  • Follow the manufacturer’s instructions for assembling the filter.
  • Pour the collected rainwater into the filter’s reservoir.
  • Allow the water to pass through the filter into a clean container.
  • Repeat the process if necessary to ensure thorough filtration.

3. DIY Charcoal Filter

If you don’t have access to a commercial water filter, you can create a simple DIY charcoal filter using readily available materials. Charcoal is an excellent natural filter that can help remove impurities and improve water quality.

Here’s how to make a DIY charcoal filter:

  • Find a clean container and gather the following materials: sand, gravel, activated charcoal (available at pet stores), and a piece of cloth.
  • Drill or punch a small hole in the bottom of the container.
  • In layers, add the following materials to the container: gravel, sand, activated charcoal, and cloth.
  • Pour the collected rainwater into the filter and allow it to pass through the layers. Collect the filtered water in a clean container.

4. Solar Disinfection

Solar disinfection, or SODIS, is a method that uses sunlight to kill or inactivate pathogens in water. It is a simple and cost-effective way to purify rainwater, especially in sunny environments.

Here’s how to use solar disinfection:

  • Collect rainwater in a clear plastic or glass bottle.
  • Remove any floating debris or particles from the water.
  • Place the bottle in direct sunlight for at least six hours.
  • If the water is cloudy, it may require additional time in the sun.
  • After disinfection, the water may be slightly warm but safe to drink.

5. UV Water Purifiers

UV water purifiers use ultraviolet light to kill or inactivate bacteria, viruses, and protozoa. They are compact, portable devices that are an excellent addition to any emergency preparedness kit.

Here’s how to use a UV water purifier:

  • Follow the manufacturer’s instructions for operating the UV water purifier.
  • Ensure that the water is free from large particles or debris.
  • Submerge the UV purifier in the water, and activate the device.
  • Stir the water occasionally to ensure thorough exposure to UV light.
  • Wait for the recommended time stated in the instructions.
  • The water is now safe to drink.

6. Use Water Purification Tablets

Water purification tablets are a convenient and lightweight option for treating rainwater. They contain chemicals that kill or inactivate pathogens, making the water safe to consume.

Here’s how to use water purification tablets:

  • Read and follow the instructions provided by the manufacturer.
  • Drop the required number of tablets into the collected rainwater.
  • Wait for the recommended time stated in the instructions.
  • Shake or stir the water to ensure proper distribution of the tablets.
  • The water is now ready to drink.

7. Distillation

Distillation is a more advanced method of water purification that involves collecting and condensing the steam from boiling water. This process effectively removes impurities, leaving you with clean, drinkable water.

Here’s how to distill rainwater:

  • Collect rainwater in a pot and place it on a heat source.
  • Set a heat-resistant container next to the pot.
  • Cover the pot with a lid, turned upside down, and filled with ice or cool water.
  • As the pot heats up, steam will rise and collect on the lid.
  • The steam will condense and drip into the waiting container.
  • Collect the distilled water and transfer it to a clean container for storage.


When it comes to survival, having a reliable source of clean drinking water is crucial. By learning various methods to filter and purify rainwater, you can ensure that you have safe and potable water in any situation.

Remember to always prioritize safety and follow the recommended guidelines for each method. Regularly check and maintain your filtration and purification equipment to ensure its effectiveness.

Stay prepared, stay hydrated!

My 2 Cents

Having the knowledge and skills to filter and purify rainwater is an essential survival skill. In emergency situations, having access to clean drinking water can mean the difference between life and death. Here are a few additional tips to keep in mind:

– It’s always a good idea to have multiple methods of water filtration and purification available. This allows you to adapt to different situations or address any equipment failure.
– Consider investing in a portable water testing kit to monitor the quality of your filtered or purified water. This will provide you with peace of mind and ensure that you are effectively removing contaminants.
– Prioritize the collection of rainwater from clean, non-polluted surfaces. Avoid collecting rainwater from roofs or surfaces that may contain harmful substances or contaminants.
– If you are unsure about the safety of collected rainwater, it’s best to err on the side of caution and treat it before consumption. Remember, it’s always better to be safe than sorry when it comes to waterborne illnesses.
– Don’t overlook the importance of proper storage for your filtered or purified water. Use clean, airtight containers to prevent contamination and store the water in a cool, shaded area to reduce the growth of bacteria or algae.

Remember, being prepared is the key to survival. Stay informed, learn new skills, and always prioritize your safety and well-being.