Does it really matter whether your filter removes 99.9% versus 99.999%?
This video is as much about concepts in filtration as it is about the filters themselves. It uses published, scientific studies on real-world concentrations of pathogens found in wilderness waters and lab-tested levels of available filtration rates to examine the question:
How much Safety is “enough”?
Analyzes risk assessment of the threats from bacteria and protozoa: giardia, cryptosporidium, E. coli.
Also includes discussion of service life (gallons filtered), flow rate, backflushing, and combination treatment methods.
Part 3 in a continuing series on Backcountry Water Treatment methods. See the whole series here:
00:35 Core Function
01:38 Risk Tolerance (How much safety is enough?)
05:23 Minimum Effective Dose
06:18 Concentration vs. Dose
07:16 Cyst Acquisition Rates
10:14 Odds of Getting Sick
11:58 The Stakes
25:47 Cryptosporidium parvum
27:06 Bacteria / Total Coliforms
28:50 Colony-Forming Units
29:48 E. coli
38:13 The Filters
39:05 Service Life
42:55 Flow Rate
51:49 Combining Methods
For more on Hydration Strategies and Electrolyte Balance, check out the series on Performance Nutrition for Backpackers: