Water Purification Calculator
Calculate water purification capacity and supplies needed for emergencies. Compare treatment methods and plan your backup water supply.
Calculate Water Purification Needs
Understanding Water Purification
Clean water is the most critical emergency supply. While storing water is ideal, you may need to purify additional water from alternative sources. Different purification methods address different contaminants:
| Method | Bacteria | Viruses | Parasites | Chemicals |
|---|---|---|---|---|
| Boiling | Yes | Yes | Yes | No |
| Chlorine/Bleach | Yes | Yes | Partial | No |
| Iodine Tablets | Yes | Yes | Partial | No |
| UV Light | Yes | Yes | Yes | No |
| Filter (0.2 micron) | Yes | Most | Yes | Some |
| Carbon Filter | No | No | No | Yes |
Purification Methods Compared
Boiling
Pros: Most reliable, kills all pathogens, no supplies needed beyond fuel
Cons: Requires fuel, time-consuming, doesn't remove chemicals
How: Bring to rolling boil for 1 minute (3 minutes above 6,500 ft elevation)
Gravity/Pump Filters
Pros: Fast, high capacity, removes particulates, no fuel needed
Cons: Expensive upfront, filters need replacement
Capacity: 1,000-100,000+ gallons depending on model
Chemical Treatment (Tablets/Bleach)
Pros: Lightweight, inexpensive, long shelf life
Cons: Wait time, taste, less effective on parasites
Bleach ratio: 8 drops per gallon (or 1/8 tsp), wait 30 minutes
UV Treatment
Pros: Fast, effective, no chemicals
Cons: Requires batteries/power, doesn't work on cloudy water
Pre-Treatment for Cloudy Water
If water is visibly cloudy or turbid:
- Let settle for several hours
- Pour clear water off the top
- Filter through cloth or coffee filter
- THEN use your purification method
Frequently Asked Questions
What's the best water purification method for emergencies?
A multi-method approach is best. Store clean water as your primary supply. Keep a gravity filter (like Berkey or LifeStraw) for high-capacity purification. Have chemical tablets as backup. Know how to boil water if other methods fail.
How long do water purification tablets last?
Unopened tablets typically last 4-5 years. Once opened, use within 1 year. Iodine tablets have shorter shelf life than chlorine dioxide. Store in cool, dry place away from light.
Can I use pool chlorine to purify water?
No. Pool chemicals contain stabilizers and other additives unsafe for drinking water. Use only plain, unscented household bleach (5-9% sodium hypochlorite) or products specifically designed for water purification.