# Improved Berkey Design



## Prepadoodle

After some poking around, I am convinced that the black Berkey filters are the only way to go when it comes to water purification. These filters, though expensive, are the only ones I have seen that will actually purify the water instead of just filtering it. This means they remove virtually all of the pathogens (like bacteria) and make secondary treatment unnecessary.

As I see it, the basic Berkey system has an irritating design flaw: the bottom of the filter does most of the work. Once the water level drops, the top isn't used at all. This reduces flow rates and shortens the life of the filter. There has to be a better way, and there is...










The picture on the left shows the typical setup. As you can see, the top of the filter isn't doing much.

But if you make a setup as shown on the right, you will make full use of the filter almost all the time. I would size the lower extension so that it holds about 1 quart plus the filter. If you have 4 gallons in the top part (16 quarts) all but the last quart will use 100% of the filter. Since 15/16 = .9375, this means that the whole filter will be used at least 94% of the time.

There are 2 benefits from doing it this way; the water in the extension will be pressurized a little the weight of the water above and pass through the filter faster, and since you are using the whole filter, it should last longer. I would conservatively estimate that the flow rate and filter life will both double. This means that a single filter modified unit would give you the same performance as a 2 filter standard unit. You would basically be cutting the filter costs in half.

There are also 2 disadvantages: the whole thing would be a little taller, and it would cost more time and effort to make. Standard Berkey units are kind of tall and thin. If you used wider, shorter containers (like a 20 quart stock pot), the overall height of the modified unit wouldn't be that much taller than a standard Berkey unit. The sdditional cost and time needed to build a modified unit would be offset by the savings in filters.

There are several ways you could actually make this thing. It could be all stainless and either TIG welded or silver soldered. It could be all plastic and be epoxied together. It could be a combination of materials, etc. etc, etc.


----------



## Nathan Jefferson

Great idea! I really do hate the fact that only a tiny part of the filters do the majority of the work... I reduced the # of filters I use to help offset this, but then the flow rate is sooooo slow.


----------



## Inor

I had this exact same question when I bought our Berkey. I even called their customer support number and after being passed around to a few different people, I finally found someone that "seemed" to have some engineering knowledge and he explained it something like this:

The way the filters are designed, the water does not pass through the filter because of the weight of the water in the reservoir, rather the filter material absorbs the water from the reservoir and disperses it evenly throughout the filter material. When the filter material is fully saturated and cannot hold anymore, the excess water begins to condense as droplets on the inside hole in the filter and drip through to clean water container. So, even if the top of the filter is not submerged, it is still "wicking" the water up and performing the filtering operation. He explained it as using a similar principle to how a kerosene lamp wick will absorb kerosene from a bottom reservoir and move the oil to the top of the wick where it is burned. It is also why the Berkey filters have to be "charged" with water before you put them in the device or they will not work.

Note: This explanation could be complete B.S. as I have not seen the engineering docs on the filters themselves. But at the time, it satisfied me enough to shell out the $$$ to buy one. :smile: But, the little bit of testing we have done with the device does appear to support the explanation though. The tops of the filters do stay completely wet even when the water level in the reservoir is only an inch or two deep.


----------



## Prepadoodle

I can see all that, good to know. I was kinda wondering if some sort of capillary action was going on there. If the top of your filter stays wet, it kinda confirms that.

If those filters are at all porous, increased pressure would improve flow. I saw a YouTube by a guy who used a small pump to pressurize his system to only 2 psi and the flow increased a lot. He was only using ceramic filters though, so I dunno if that would help with the black Berkey ones.

Screw it, I'm gonna order a set of them and play around a little. I have been resisting this because I want to move soon and don't need a bunch of new stuff to be packed and whatnot, but water is a primary need and I don't want to get caught short.

Thanks for the info Inor, I'll keep ya posted.


----------



## Prepadoodle

OK, this project is officially cancelled. LOL

I was going to use clear acrylic tubing for my down extension, but it's like $14 a foot with a 6 foot minimum. By the time all was said and done, the one I was gonna make wouldn't have been much cheaper and no guarantees it would work better anyway.

So I ordered a Big Berkey and 2 LifeStraws.

Once I get into my new location (which might be 6 months from now the way it's going) and set up a shop again, I'll get back into mad scientist mode and start experimenting. I also want to play around with making my own batteries. Oh yes, much mad scientist experimenting!

Thanks again Inor, I have the feeling you saved me a lot of trouble for nothing.


----------



## Inor

Prepadoodle said:


> OK, this project is officially cancelled. LOL
> 
> I was going to use clear acrylic tubing for my down extension, but it's like $14 a foot with a 6 foot minimum. By the time all was said and done, the one I was gonna make wouldn't have been much cheaper and no guarantees it would work better anyway.
> 
> So I ordered a Big Berkey and 2 LifeStraws.
> 
> Once I get into my new location (which might be 6 months from now the way it's going) and set up a shop again, I'll get back into mad scientist mode and start experimenting. I also want to play around with making my own batteries. Oh yes, much mad scientist experimenting!
> 
> Thanks again Inor, I have the feeling you saved me a lot of trouble for nothing.


If you just whacking together a quick prototype for testing, could you just use PVC? It is cheap, easy to weld with the purple juice, and available everywhere. - Now you have me wondering. :?


----------



## MrsInor

Absolutely NO new projects until at least two thirds of the ones started are finished.


----------



## Prepadoodle

Now you have me wondering again. If the main action of the filter takes place due to this wicking effect, why do you have to prime the filters? Capillary action should work even if the filters were completely dry to start.

The filters have to be at least a little porous. Being in direct contact with slightly pressurized water would almost certainly make them work faster. If the top was exposed to pressurized air, I am guessing the air would escape through the filter, releasing the pressure. Air, after all, is thinner than water.

But my main concern isn't about speed. I will probably fill it the night before I need it, then replace water as I use it. If you do this, you will always have clean water available.

If the entire filter is being used due to the wicking action, there seems little reason to do anything, even if it does take longer that way. 

Because the pores are so small, I would imagine the filters will stay wet a long time, even with no water in the system. The air in the container would be near saturation, so the moisture on the surface can't evaporate unless the temperature increases or drier air is introduced. Once the surface of the filter does dry through evaporation, water would migrate from inside the filter seeking equilibrium. With the lid on, this would take a long time.

What I'm saying here is that I can't think of any way to test whether the whole filter is actually being used or not.

I should have my system by Friday. Maybe once I get my hands on it I will figure out a way to see if the whole filter is being used or not.

Meanwhile, I am thinking about how I can make batteries that will run on tap water.


----------



## Inor

Prepadoodle said:


> Meanwhile, I am thinking about how I can make batteries that will run on tap water.


That's easy...

Take a big glass of tap water up to Walgreen's. Throw it on the clerk. While she is freaking out about you throwing tap water on her, grab a bunch of batteries off the shelf and run like hell!


----------



## Prepadoodle

I'm thinking more along the lines of taking a piece of galvanized pipe and putting an end cap on it. Then taking a piece of copper pipe, insulating one end with electrical tape and sliding it into the galvanized pipe so it doesn't touch. Fill the thing with tap water and BAM, you have a battery.

I have a new Fluke multimeter coming tomorrow, so I'm gonna start experimenting with home-made batteries and will let ya know what I learn. My goal is to be able to MacGyver batteries out of stuff you find laying around.


----------



## Inor

Prepadoodle said:


> I'm thinking more along the lines of taking a piece of galvanized pipe and putting an end cap on it. Then taking a piece of copper pipe, insulating one end with electrical tape and sliding it into the galvanized pipe so it doesn't touch. Fill the thing with tap water and BAM, you have a battery.
> 
> I have a new Fluke multimeter coming tomorrow, so I'm gonna start experimenting with home-made batteries and will let ya know what I learn. My goal is to be able to MacGyver batteries out of stuff you find laying around.


In all seriousness, please do let us know what you figure out. Homemade batteries are something that has interested me since I was a kid and I made a Radio Schlock one with a lemon.


----------



## Seneca

Inor said:


> If you just whacking together a quick prototype for testing, could you just use PVC? It is cheap, easy to weld with the purple juice, and available everywhere. - Now you have me wondering. :?


That's my thought, it's the filter that does the work the rest is open to modification.


----------



## Prepadoodle

I think there is a way to test this. Take a piece of PVC pipe big enough to hold the filter and maybe 2 feet long. Get a cap, drill it, then install the filter and jam the cap in place. Fill the tube with water and put a bowl under it to catch the water.

Then set a timer for like 15 minutes and wait. When the timer goes off, reset it and measure the water with a measuring cup or whatever. Do this every 15 minutes until it's all filtered.

If there is no difference in the amount of water, then the whole filter is being used all the time AND pressure doesn't matter.

If the output decreases over time, then increasing pressure increases flow.

At this point, you would have to plot the output vs time and look at the line. If the line connecting the data points is straight right to the end, then the whole filter is being used due to this "wicking action." If there is a "bend" (further drop in output) in the line once the filter top becomes exposed, then the whole filter isn't being used because the pressure depends entirely on the height of the water and should graph as a straight line.

I would bet that there would be a decrease in output over time, showing that pressure is a factor. I would also expect to see a bend in the line because I don't believe the whole filter is being used all the time, no matter what their customer service says. 

Right now, I'm distracted with batteries and won't be able to try this for some time. If someone else wants to do it, please do!


----------



## Prepadoodle

The graphs would look something like this...









The first would be how it looks if pressure doesn't matter and the whole filter is being used all the time. The second would where pressure matters, but the whole filter is always being used. The last one would show that both pressure and filter coverage make a difference.

There should be a 4th case, where pressure doesn't matter but filter coverage does. In this one, it would be a horizontal line until the filter top is exposed, then output would drop off. Im' not gonna redraw the bloody thing to add it though, so use yer imagination.


----------



## Inor

Prepadoodle said:


> The graphs would look something like this...
> 
> View attachment 2310
> 
> 
> The first would be how it looks if pressure doesn't matter and the whole filter is being used all the time. The second would where pressure matters, but the whole filter is always being used. The last one would show that both pressure and filter coverage make a difference.
> 
> There should be a 4th case, where pressure doesn't matter but filter coverage does. In this one, it would be a horizontal line until the filter top is exposed, then output would drop off. Im' not gonna redraw the bloody thing to add it though, so use yer imagination.


Placing my bet now based on nothing but intuition...

I expect the output to drop off some once the top of the filter is exposed to air. But, that does not necessarily mean the entire filter is not still filtering as there is less surface area of the filter exposed to water. Thus, the draw would be slower. I would expect a flat graph until the top is exposed then a more rounded graph as the water level drops. As I said, I do not base this on anything scientific, just a (hopeful) bet that the Berkey people did not lie to me.


----------



## Prepadoodle

Inor, they _so_ lied to you.

Actually, you might just have gotten one of those people who can't admit they don't know the answer. I'm thinking that, if it wicked up water, you wouldn't have to prime the filters. I freely admit I don't know this for sure, it's just a hunch.

Anyway, my bet is on the crooked line. I'm pretty sure pressure is all that moves water through any part of the filter.

So ask Mrs Inor if you can test it one way or the other please!


----------



## Inor

Prepadoodle said:


> Inor, they _so_ lied to you.
> 
> Actually, you might just have gotten one of those people who can't admit they don't know the answer. I'm thinking that, if it wicked up water, you wouldn't have to prime the filters. I freely admit I don't know this for sure, it's just a hunch.
> 
> Anyway, my bet is on the crooked line. I'm pretty sure pressure is all that moves water through any part of the filter.
> 
> So ask Mrs Inor if you can test it one way or the other please!


HAHAHA! Will do sir. I am home this week so I will do the test as you prescribe.


----------



## Seneca

Filters aside, the Berkey spigot looks to be of the inexpensive variety, how do those hold up or should one look into replacing it from the get go...


----------



## MrsInor

Prepadoodle - Inor can play with the Berkey after he finishes his cabinet in the garage so I can have the shelves he is replacing with said cabinet. Then I can finish cleaning up downstairs and we can put this place on the market.


----------



## Montana Rancher

Prepadoodle said:


> Inor, they _so_ lied to you.
> 
> Actually, you might just have gotten one of those people who can't admit they don't know the answer. I'm thinking that, if it wicked up water, you wouldn't have to prime the filters. I freely admit I don't know this for sure, it's just a hunch.
> 
> Anyway, my bet is on the crooked line. I'm pretty sure pressure is all that moves water through any part of the filter.
> 
> So ask Mrs Inor if you can test it one way or the other please!


I am a terrible politician so don't flame me too bad for this.

I hate it when someone says "they lied to you" and in the next sentence say its just a hunch.

The bottom line is the Berkey is the best water filter out there for the money, I say quit dissing it on technicalities.


----------



## pfwag

Berkleys are OK for sitting on the counter. There, are, however, cheaper alternatives and as the thread author noted you can make one yourself.

However, be aware that all the candle filters, along with most filters, will not filter out a virus as they are just too small and the filter's pores are too big. You still need to do something to kill virus. Chemicals, heat, or UV light is needed for that. The simplest and cheapest way is to use some chlorine (regular ole Clorox). You can use a carbon filter (even the better pitcher ones) to remove the chlorine if desired.

However, there are better and more cost effective solutions.

Build a gravity filter using a bucket, ten feet of tubing, and a really good solid block carbon filter. It takes the Berkley principle and expands on it at a much lower cost. If your "survival water" is dirty, you can also add a pre-filter so you don't clog up the carbon block filter. BTW, pre-filter dirty water going into a candle filter too.

Simply put the dirty water in a bucket at a higher elevation and let gravity do the work of pushing the water through the carbon block filter.

If you want to buy a kit, go to Premium Water Filters - Home and look for the "emergency filters." There are a number of different options.

This is the best place and pricing I've found for all things filters and Marc, the owner, knows filters. Marc only sells quality filters, not the Chinese junk. Caveat emptor when it comes to water filters.

And he has one filter that will filter out a virus. However, I'd still use some chlorine.

I have one of his gravity bucket filters, with all the parts in the bucket, wrapped up and stored away for "just in case."

Oh, and the chlorine in Clorox decays over time. If I remember correctly, about 50%/year, so get some chlorine test strips. Even better, get calcium hypochlrorite. Just a pound of the stuff will treat something like 10,000G of water. But the stuff isn't play dough so be sure to read and follow the precautions. And never store it in a metal container, even the lid, or store it inside your house.


----------



## PrepperDogs

I am not in the Berkey fan club.

The initial cost is expensive as are the filters. The filters only last 3,000-6,000 gallons depending on how many you use and the cleanliness of the water.

How many Berkey filters do you think you'll need for 3 months? 6 months? A year? The cost outlay is prohibitive.

What I do like are hollow fiber membrane filters. Lower initial cost and will last for a minimum of 1,000,000 gallons. The addition of a DIY inline charcoal filter will also remove solids, chemicals, and heavy metals.

A 0.02 micron absolute pore purifier will remove everything on this list:










With this purifier and my charcoal filter I can produce 150+ gallons of water per day. Total cost $133.


----------



## Prepadoodle

PrepperDogs said:


> How many Berkey filters do you think you'll need for 3 months? 6 months? A year? The cost outlay is prohibitive


If a set of filters will last 6,000 gallons and I drink 2 quarts a day and my GF drinks 2 quarts a day, that's 365 gallons per year so the filters should last over 16 years. The cost of the system was about $270 with filters, which works out to be about 4.5 cents a day. If I buy a gallon of water a day at the supermarket, it would cost me $1 a day, not counting the time, effort, and gas to go get it. So bottled water is over 22 times more expensive.

Anyway, that's the way I look at it.


----------



## Paltik

I'm researching a series of articles on water treatment now and am finding myself increasingly attracted to the Big Berkey. While most Berkey filters do not filter viruses (though you can pre-treat with chlorine or UV), the Big Berkey does about as much as any one filter can do--viruses, VOC's, heavy metals, chemicals including pesticides, chlorine, and fluoride, etc. The more I'm learning, the cheaper that big up-front price is looking. (In the meantime I'm real happy with my Sawyer filter and my Steripen.)


----------



## PrepperDogs

Prepadoodle said:


> If a set of filters will last 6,000 gallons and I drink 2 quarts a day and my GF drinks 2 quarts a day, that's 365 gallons per year so the filters should last over 16 years. The cost of the system was about $270 with filters, which works out to be about 4.5 cents a day. If I buy a gallon of water a day at the supermarket, it would cost me $1 a day, not counting the time, effort, and gas to go get it. So bottled water is over 22 times more expensive.
> 
> Anyway, that's the way I look at it.


I would suggest that you rethink your water consumption. The *minimum* required per person, to sustain life, is one gallon per day. This does not take in account your water needs for cooking, hygiene, laundry, medical emergencies, and animal usage.

I prep for 3. I estimate my total water usage at 15 gallons per day, which is conservative.


----------



## PaulS

PrepperDogs said:


> I would suggest that you rethink your water consumption. The *minimum* required per person, to sustain life, is one gallon per day. This does not take in account your water needs for cooking, hygiene, laundry, medical emergencies, and animal usage.
> 
> I prep for 3. I estimate my total water usage at 15 gallons per day, which is conservative.


Potable water versus other uses. 3 gallons for drinking - cooking can be done with and counted in your drinking water. the rest doesn't require filtered water. Medical emergencies you should be using water treated with chlorine or something else anyway. you can wash your hands and do the dishes in rain water with a touch of bleach to help the soap do its job.

My point is you don't have to use filtered water for all of it.


----------



## PrepperDogs

PaulS said:


> Potable water versus other uses. 3 gallons for drinking - cooking can be done with and counted in your drinking water. the rest doesn't require filtered water. Medical emergencies you should be using water treated with chlorine or something else anyway. you can wash your hands and do the dishes in rain water with a touch of bleach to help the soap do its job.
> 
> My point is you don't have to use filtered water for all of it.


Seems like more work to me. A proper filtration system shouldn't require any extra work or maintenance with the exception of a filter cleaning now and then. I would rather have the ability to have enough water on hand, at all times, no matter what the situation requires.

Excess water production also provides me with one of the best bartering items there is....along with salt.


----------



## Prepadoodle

I've never consumed a gallon of water in a day, so I guess I must be dead. Who knew?

Edited to add:

Since water is such a vital part of survival, maybe we should look at how much you need to survive.

As a starting point, the Mayo Clinic says, "So how much fluid does the average, healthy adult living in a temperate climate need? The Institute of Medicine determined that an adequate intake (AI) for men is roughly 3 liters (about 13 cups) of total beverages a day. The AI for women is 2.2 liters (about 9 cups) of total beverages a day. "

In an SHTF scenario, I would be using the Berkey as my main water supply. I wouldn't be using it to filter ALL the water needs of the household, and be using it as little as possible to make it last as long as possible. As pointed out in the original post, I am looking for ways to extend the filter life.

There is a difference between the amount of liquid suggested and the amount you need to survive. Of course you can survive on less than the Mayo clinic suggests as "adequate." How much less depends on a lot of factors, like climate, how active you are, and your individual metabolism.

There is a difference between how much liquid you need and how much drinking water you need. We get liquids from most of the foods we eat. If your main stores are canned goods, you would need less drinking water than if most of your food was freeze dried. 

I'm not a Berkey salesman, but it's the one I bought. Had I heard of the hollow fiber membrane filters before I bought it, I would have looked into it. As far as I am concerned, it's water under the bridge because I now have what I now have. Perhaps you should start a thread about them. Maybe it will help other people make more informed decisions when it comes time for them to get a filter system.


----------



## PrepperDogs

Prepadoodle said:


> I've never consumed a gallon of water in a day, so I guess I must be dead. Who knew?
> 
> Edited to add:
> 
> Since water is such a vital part of survival, maybe we should look at how much you need to survive.
> 
> As a starting point, the Mayo Clinic says, "So how much fluid does the average, healthy adult living in a temperate climate need? The Institute of Medicine determined that an adequate intake (AI) for men is roughly 3 liters (about 13 cups) of total beverages a day. The AI for women is 2.2 liters (about 9 cups) of total beverages a day. "
> 
> In an SHTF scenario, I would be using the Berkey as my main water supply. I wouldn't be using it to filter ALL the water needs of the household, and be using it as little as possible to make it last as long as possible. As pointed out in the original post, I am looking for ways to extend the filter life.
> 
> There is a difference between the amount of liquid suggested and the amount you need to survive. Of course you can survive on less than the Mayo clinic suggests as "adequate." How much less depends on a lot of factors, like climate, how active you are, and your individual metabolism.
> 
> There is a difference between how much liquid you need and how much drinking water you need. We get liquids from most of the foods we eat. If your main stores are canned goods, you would need less drinking water than if most of your food was freeze dried.
> 
> I'm not a Berkey salesman, but it's the one I bought. Had I heard of the hollow fiber membrane filters before I bought it, I would have looked into it. As far as I am concerned, it's water under the bridge because I now have what I now have. Perhaps you should start a thread about them. Maybe it will help other people make more informed decisions when it comes time for them to get a filter system.


I drink approximately 3/4 gallon of water per day. More when I'm out in the shop or working in the fields. And like the Mayo said, it's all dependent on a number of variables. I contend with 90%+ humidity and 90+ degree weather daily.

Now that you have your Berkey, be wary of imitation filters. Also be extremely careful when changing and storing them. I'm not sure if they changed the design but they are prone to breakage.


----------

