1. #1Survivor Filter Straw Ultra Filter ReplacementSurvivor Filter$0.0006/gal
2. #2SURVIVOR FILTER™ Pure 10K - Replacement Chlorine FilterSurvivor Filter$0.0080/gal
3. #3Puribag Micro - Mini membrane water filterUncharted Supply$0.0174/gal
4. #4Puribag Pro - Membrane Filter KitUncharted Supply$0.0227/gal
5. #5LifeStraw Peak Series StrawEcho-Sigma$0.0260/gal
6. #6SURVIVOR FILTER™ Max, 2-Stage Fluoride and Chlorine In-Line Home FilterSurvivor Filter$0.0400/gal
7. #7Puribag Pro Portable Water Purification SystemUncharted Supply$0.0492/gal
8. #8Survivor Filter Straw Carbon Filter ReplacementSurvivor Filter$0.0566/gal