I’m considering a gravity water filtration system. These can be a key element to personal health especially when you’re dealing with water sources that are not sanitary. Here’s what I’m discovering so far:
1. ) La Natural Terracotta Base with ceramic filter
Combines old technology (naturally cooling effect of terracotta with modern filtration technology. Pour 1 gallon of water into container and gravity pulls it through a “dual micro-pore ceramic/activated carbon filter that removes 95% of chlorine, pesticides, heavy metals including iron, aluminum, lead and 100% cryptosporidium, giardia and sediment.” Can filter 6 gallons a day…if you keep up with filling it. The filter lasts one year or 2500 gallons.
Costs: $198 (from watersavers.com)
Replacement filter: $72
Positives: Natural cooling effect is nice.
Negatives: Small capacity, heavy for shipping and fragile for transport. Pricing seems high compared to more higher tech and ones with better ratings than this.
2) Big Berkey
This stainless steel construction breaks down to only 12 inches tall when not in use and is know for it’s ability to provide fresh clean water even from icky river or swamp water as its dual or quad filters remove sediment, odor, bacteria, and chemicals.
Storage: 2.25 gallons
Filtration: 3.5 gal/hr.
Filters: 4 elements
Positives: Stainless steel, packing down to small size for transport. Storage capacity and nice filtration rate.
Negatives: 8 pound weight takes up almost a 5th of what you’re allowed in standard checked baggage if you’re flying anywhere. (If you’re putting it on the cabinet or driving it in to your campsite then probably great.) Not a lot of info on the specs of the filters.
I’ve seen this one in use on the mission field and received very positive reviews from a missionary who used it. The three ceramic filters remove bacteria, cysts, algae, protozoa, sediment, dirt, spores, some viruses and other disease causing agents to .2 microns in size. (according to the filter guide on Heartspring.net, “Laboratories consider a filtering medium with an effective pore size of .01 micron to .45 micron to be bacteriologically sterile….”
Using this Katadyn water filter system you can use water from streams, rivers, and lakes for drinking, cooking, cleaning, and so on. The Ceradyn gravity drip filter system will reduce organisms that cause such diseases as cholera, dysentery, typhoid fever, and giardia.
Capacity: 2.6 gallon (10 liters)
Number of filters: 3
Filtration rate: 1gal/hr.
Weight: 7.25 pounds
Cost: $249 (Although I just saw one go for $91 on eBay)
Filter Replacement: $60 ea.
Positives: Highly recommended and long lasting. Although not recommended one missionary family used the same filters for about 10 years by cleaning off the exterior of the filter every once in a while. Seemed to work for them…
Negatives: Filtration speed is slow (but the effectiveness seems to outweigh this.)
I’ve seen this ceramic gravity filter in use in Guatemala in home settings and the owners seem pretty happy with it. The ONIL provides “up to 10 gallons of safe drinking water every 24 hours” .
Capacity: 10 gallons
Number of filters: 1
Filtration rate: 10 Gallons/24hours (0.5 to 0.8 microns)
Weight: 7 pounds
Negative: Requires cleaning of the filter weekly.
5) Other non-typical filtration systems especially valuable in third world applications: