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View Full Version : Non-portable water filters (aka Gravity Filters)



TheSwally
08-13-2008, 06:44 PM
There is a fantastic thread from ThermoCouple in this forum describing different portable filters. I thought it would be helpful to start another thread on gravity filters.

Gravity filters usually consist of an upright canister, divided into two sections. The top part is where you pour the water in. There are holes in the bottom of this section in which you screw your filter(s). Water filtrates into the filter and drips into the lower container. A spigot in the bottom container allows for the clean water to be dispensed. There are no mechanical or movable parts (hence it's name "gravity filter").

These filters are great for home or a base camp. Simply pour the water in top, wait for the water to filter into the bottom tank (usually a slow process, as in a few gallons per hour), then get water from the bottom.

I researched for a week before I bought one. The two top brands seem to be Aqua Rain and Berkey. I settled on the Berkey. It breaks down into 2 canisters that can be nested for storage, which I was very happy about. One Berkey model is pictured below.

http://www.arkinstitute.com/Ark_ws_Big_Berkey_main_photo_on_lake.JPG

Berkey makes 5 models that vary in size (and the number of filters they will hold). From smallest to biggest they are:

Travel
Big
Royal
Imperial
Crown

For my family of 4, I decided on the Royal model. It holds 3.25 gallons in the bottom tank, and can process 4 gallons per hour if you have both filters added. The best price I found for these was at www.disasterstuff.com (http://www.disasterstuff.com). Once you add the item to your cart and checkout, 22% is taken off of the listed price, plus he had free shipping at the time (and may still have free shipping).

I made a spreadsheet comparing the 5 models, if anyone is interested I'm happy to email you a copy.

Julie
08-13-2008, 07:00 PM
This is the one that I have. I had to teach a preparedness class and I really pushed the Berkey because we live near a river and it will purify the river water. It made sense to my neighbors to get one and I know several got one.

NRA
08-13-2008, 07:29 PM
Good info. Thanks!

DMGNUT
08-13-2008, 11:48 PM
Don't rule out the Katadyn brand. They make a "poly" version that is otherwise the same. Plastic in stead of stainless steel, makes it much less expensive.

TheSwally
08-14-2008, 12:31 AM
Good point, DMG. Berkey has a similar model, althought I didn't include it because it is my opinion when you are talking about $20 or $30, I'd much rather spend a little more and have the stainless steel for durability. But it is still an option. It's called the Berkey Light.

http://www.disasterstuff.com/store/pc/Berkey-Light-Water-Purifier-System-2-75-CAP-4-GPH-20p64.htm

Alma the Younger
08-14-2008, 07:02 PM
I have a Katadyn Gravidyn filter as well.

http://www.nitro-pak.com/images/2020-200x200.jpg

I have come to trust the Katadyn brand. They are excellent quality and the price was right.

NitroPak has them on sale for $188.90 with free shipping. That's not too bad.

This model will provide up to 13 gallons a day with a life of 39K gallons before you need to replace the filters. The filters have a pore size of .02 microns and are impregnated with silver. They also have an activate charcoal interior to eliminate bad tastes.

I also have a Katadyn pocket filter for mobile use.

My plan is to use my 55-gallon barrels of water for washing and cleaning. For cooking and general drinking I'll pump water out of the barrels and pour it into the Gravidyn filter. We also have a number of canals in our area where water can be found.

419!

Alma the Younger
02-20-2009, 11:39 PM
A follow-up: My plan was to have two Gravidyn filters. I figured that the two working together would provide double the water and that's not a bad deal.

Well today I got my second one. Now, I feel better about the quanity of drinking water I'll be able to filter. Since I live in a desert, this is a big deal for me.

419!

threepercent
02-21-2009, 10:06 AM
http://www.alpharubicon.com/kids/homemadeberkeydaire.htm

North_Star
02-21-2009, 10:11 AM
We like our Big Berkey.

foust1012
06-21-2010, 11:42 AM
There is a fantastic thread from ThermoCouple in this forum describing different portable filters. I thought it would be helpful to start another thread on gravity filters.

Gravity filters usually consist of an upright canister, divided into two sections. The top part is where you pour the water in. There are holes in the bottom of this section in which you screw your filter(s). Water filtrates into the filter and drips into the lower container. A spigot in the bottom container allows for the clean water to be dispensed. There are no mechanical or movable parts (hence it's name "gravity filter").

These filters are great for home or a base camp. Simply pour the water in top, wait for the water to filter into the bottom tank (usually a slow process, as in a few gallons per hour), then get water from the bottom.

I researched for a week before I bought one. The two top brands seem to be Aqua Rain and Berkey. I settled on the Berkey. It breaks down into 2 canisters that can be nested for storage, which I was very happy about. One Berkey model is pictured below.

http://www.arkinstitute.com/Ark_ws_Big_Berkey_main_photo_on_lake.JPG

Berkey makes 5 models that vary in size (and the number of filters they will hold). From smallest to biggest they are:

Travel
Big
Royal
Imperial
Crown

For my family of 4, I decided on the Royal model. It holds 3.25 gallons in the bottom tank, and can process 4 gallons per hour if you have both filters added. The best price I found for these was at www.disasterstuff.com (http://www.disasterstuff.com). Once you add the item to your cart and checkout, 22% is taken off of the listed price, plus he had free shipping at the time (and may still have free shipping).

I made a spreadsheet comparing the 5 models, if anyone is interested I'm happy to email you a copy.

I love the Berkey! It is a great system. I recently bought mine from www.berkeyproducts.com and have been very satisfied. They do offer free shipping and when you buy one you can get 2 free PF-2 filters included. Great deal and great people to work with.