# How to refill water filter automatically?



## laurie71 (Oct 31, 2014)

I'm trying to figure out a way to automatically refill my Berkey water filter. I plan to extend the line feeding the water dispenser / ice maker on the fridge to supply the water filter. I'm OK with modifying the Berkey for this, I just need to figure out what kind of water valve system will work...

The filter has two stacked tanks; the top one is the pre-filter fill tank, the bottom one is the holding tank for filtered water. What I want to achieve is that when the holding tank is empty, the fill tank gets topped off. I can't just keep the top tank filled at all times; the water would keep draining through the filters and overflow the holding tank. 

What I'm thinking is a pair of float valves; one in the holding tank that will open when the tank is empty, and one in the fill tank that will close when the tank is full. If I run the supply line through both valves that should do it, provided I can flow enough water to fill the top tank before enough water filters though into the holding tank to shut off the empty-sensor valve...

Does anyone have any better solutions, or any recommendations for suitable water valves what would work well for this applications?

Thanks!

Laurie


----------



## nealtw (Oct 31, 2014)

Welcome to the site, some of the people in know should be along soon.


----------



## frodo (Oct 31, 2014)

ice maker fill switch .if your handy. get one and modify to fit your tank. the "arm" on the ice maker can be fitted with a float
to start stop flow.  just my opinion


----------



## laurie71 (Oct 31, 2014)

I guess the ice maker fill switch would have suitable flow characteristics  Thanks, I'll look into that.


----------



## nealtw (Oct 31, 2014)

Perhaps if each tank had it's own switch but both floats were in the lower tank the one for the upper tank set lower to stop the flow to the upper tank sooner.


----------



## frodo (Nov 1, 2014)

not for nothing,  the dump is where i would look,  their's gold in that pile of junk!!!!!!

we have a local dump,  i bug the hell out of that guy, old bed frames  [angle iron]
 dryers  [motors]    grabbed an old metal fridge, turned it into a smoker


----------



## laurie71 (Nov 1, 2014)

nealtw said:


> Perhaps if each tank had it's own switch but both floats were in the lower tank the one for the upper tank set lower to stop the flow to the upper tank sooner.



Nice idea, but it takes a while for the water to pass through the filters so I woould need to manage fill levels directly.


----------



## laurie71 (Nov 1, 2014)

frodo said:


> not for nothing,  the dump is where i would look,  their's gold in that pile of junk!!!!!!
> 
> we have a local dump,  i bug the hell out of that guy, old bed frames  [angle iron]
> dryers  [motors]    grabbed an old metal fridge, turned it into a smoker



I don't even know where the dump is here, I'll have to find out...


----------



## nealtw (Nov 1, 2014)

laurie71 said:


> Nice idea, but it takes a while for the water to pass through the filters so I woould need to manage fill levels directly.



I'm stuck on the idea so I will try to back it up

The upper tank only has to refill when the lower tank needs to be refilled and it only need enough water to be filtered and not to much.

Without knowing any numbers, i will just make some up, you would have to do some reseach to come up with the real numbers.

Let's say when the lower tank is half full when you want it to refill, that would be where you want the float to turn on the water.
You should know how much water to put in the system, let's say 1 gallon.
Now how long does it take to put 1 gallon of water in the top tank, let's say 1 minute.
How much water is filtered in 1 minute in inches, let's say 1 inch, that is where you want the float to turn off the water top the top tank.

I still see two problems 1. float travel may not be enough between on and off and this could be improved by slowing the water entering the top tank. just a valve set to drible would do that.
2. A clean filter would move water faster and would slow after time( I think)
so you would want to leave some safety in the system. Like with my numbers if it can take 1 gallon set it so it takes 3/4 gallon so when it slows down it still won't overflow.


----------



## nealtw (Nov 1, 2014)

I found this, different system but you might find the valves interesting,

[ame]https://www.youtube.com/watch?v=rhB567Gwywc[/ame]


----------



## laurie71 (Nov 1, 2014)

nealtw said:


> I'm stuck on the idea so I will try to back it up
> 
> ...
> 
> ...



There's the problem; the difference in flow rate between a new set of filters and a set that needs replacement is quite a bit... It might be possible to get something that works at both ends of that range, but I doubt it'd be optimal.


----------



## nealtw (Nov 1, 2014)

laurie71 said:


> There's the problem; the difference in flow rate between a new set of filters and a set that needs replacement is quite a bit... It might be possible to get something that works at both ends of that range, but I doubt it'd be optimal.



Perhaps if you started with a new filter and the water at a fair rate with a valve, as the system slowed you could adjust the flow up
down a little. Over time you might learn how much to decrease the flow per week or month or what have you.


----------



## laurie71 (Nov 1, 2014)

That video gives me an idea; there's a hydroponic supply store nearby, I bet I can find suitable float valves and tubing there. The auto shutoff in the video is probably not what I want, but that mini float valve might be perfect.

Thanks!


----------



## bud16415 (Nov 1, 2014)

I didn't know much about how your system works so I watched a few on line videos about that. It seems the filters are in the upper tank and work best when the lower tank is empty and the the upper tank is fully filled and allowed to drain down thru the filters. If that's the case add a third holding tank like a toilet bowl that sits and waits full. When the last drop is removed from the lower filtered tank flush the top tank and start over. The one they showed filtered fairly fast when full and took about an hour to filter all the water. 


Sent from my iPhone using Home Repair


----------



## laurie71 (Nov 2, 2014)

bud16415 said:


> I didn't know much about how your system works so I watched a few on line videos about that. It seems the filters are in the upper tank and work best when the lower tank is empty and the the upper tank is fully filled and allowed to drain down thru the filters. If that's the case add a third holding tank like a toilet bowl that sits and waits full. When the last drop is removed from the lower filtered tank flush the top tank and start over. The one they showed filtered fairly fast when full and took about an hour to filter all the water.
> 
> 
> Sent from my iPhone using Home Repair



I'm not sure of the benefit of the additional holding tank? I'm not sure the flow rate through a standard refrigerator supply line but I would expect that the upper tank should be able to be filled fast enough straight from that.

About an hour sounds about right with a new set of filters (depending on how many are installed). However, they do tend to filter more slowly as they age and start to clog.


----------



## bud16415 (Nov 2, 2014)

I guess my point was you don't want to have a set up where you don't take advantage of the full length of the filters. It's similar to how a mound septic system works with a dosing tank. You don't want to trickle water in you want the full impact and pressure of a full tank. To your point of the differential fill setup if you can fill the tank in a few minutes and it takes an hour to drain maybe that's close enough. 


Sent from my iPhone using Home Repair


----------



## laurie71 (Nov 2, 2014)

bud16415 said:


> I guess my point was you don't want to have a set up where you don't take advantage of the full length of the filters. It's similar to how a mound septic system works with a dosing tank. You don't want to trickle water in you want the full impact and pressure of a full tank. To your point of the differential fill setup if you can fill the tank in a few minutes and it takes an hour to drain maybe that's close enough.
> 
> 
> Sent from my iPhone using Home Repair



Yeah that was my thinking; I guess I should run some flow rate tests to see how long a fill would take.


----------



## nealtw (Nov 2, 2014)

If you set your fill for an old filter you should have no trouble wth a new one.


----------



## slownsteady (Nov 2, 2014)

I'd like a little background info on how the filter works now. I can guess that it's a gravity feed from the upper to lower tanks. Do you fill the upper tank by hand? What keeps the lower tank from overflowing normally? If it is sealed between the two tanks, the lower tank should not need a valve because no water can enter if it is full.


----------



## bud16415 (Nov 2, 2014)

The two halves are not sealed and the normal filters are two cylindrical filters where the water enters thru the sides and runs out a spout that pokes thru the side. So when the tank is full the whole surface is filtering and you get max flow rate and filter life I would think. You can also add filters in the lower tank for fluoride and other substances that are in line to the flow. I don't think the OP has those.

If the bottom tank is half full and you fill the top tank I would say you would get a spill. If the top tank was sealed like a bottle dispenser the the flow would stop when the water sealed air from coming in. I don't think the top lid is air tight. That's why I suggested a third dosing tank with a fill float working similar to a toilet tank. Or just run a pipe to it with a valve. I can see the awkward part of one of these is bringing a bucket from the sink to the unit everyday. 

If I had one I would run a line from the lower tank to my coffee maker. Wait I think if you pour coffee in this you get pure water out. 




Sent from my iPhone using Home Repair


----------



## laurie71 (Nov 2, 2014)

Spot on; if you fill the top tank before the lower tank is empty, you get a spill... There are holes in the bottom of the top tank that the filters install into; there is provision for up to four filters, and I have two installed now, with the other two hole plugged with blanks. 

I could probably buy an additional top tank to act as a holding tank, and let it flush into the input tank when the bottom tank empties, but I still need the mechanism to make that happen.


----------



## bud16415 (Nov 2, 2014)

That would be any kind of a container /tank with a $7.00 flush master float installed to set the water level at X gallons. Then a system in the lower tank to trigger the top tank to dose the middle tank. It could be electric or mechanical. As simple as a float in the bottom tank pulling a string to flush the top tank. I think electronic would be better float switch sends signal to solenoid on timer to open dump valve for say 5 seconds. I wouldn't wait for lower tank to be bone dry. Maybe signal at one quart left. That way the filter tank will be using the full length of the filters. Parts needed 5 gallons bucket  from home-depot, flush master valve  , sealed float switch tether type, solenoid valve, one timer relay, low voltage transformer, small electrical enclosure and of course some PEX tubing and fittings. 


Sent from my iPhone using Home Repair


----------



## slownsteady (Nov 2, 2014)

Ok, I watched a few videos and now I get the situation a bit better. My original thought is moot because the tanks are not sealed to each other.

The main problem is having to hand-fill the top tank. So in it's simplest form, you want to be able to fill the upper tank without carting the water. You could have a a manual fill setup so that all you do is turn open a valve, standby until the tank is filled and then manually shut it off. Simple, easy to operate and the only negative is standing by to turn it off. The more pressure and or the bigger the feed line, the quicker it fills, but human error (like a distraction) could result in a spill. This is where Bud's idea makes sense. By having a measured pre-fill tank, you don't risk overfilling the top tank, and that means the lower tank is also safe. And the "dump" valve means no waiting for the top tank to get it's full load (dose, I guess, but it sounds funny).
The problem with trying to control the flow at the top tank is having two outlets (four possible) from the top tank so you would need a shutoff for each in order to stop flow. It doesn't seem practical to try to control the flow at that point.

I'm actually looking at this as just an exercise. It's obvious to me that this becomes impractical very quickly, and if you are already using tap water, there are other filtration systems that make a lot more sense. Save the Berkey for it's intended use.


----------



## ProudGecko (Nov 3, 2015)

I know this thread is a year old, but I've been toying around with this exact same idea.  We have a Berkey water filter setup on our counter that seems to always be empty.

My original thought matched the ideas discussed here regarding use of a float switch.  After considering the same issues mentioned, I'm thinking of using a digital scale to monitor the amount of water in the entire system (top and bottom portions).  A Berkey that's full in the upper tank or bottom tank (or somewhere in between) should have a constant-ish weight.  If the total weight drops below a certain threshold, open a solenoid driven water valve to flow water into the upper tank until the total system weight reaches the "full" level.  

Anyone see any holes in the theory?


----------



## bud16415 (Nov 3, 2015)

ProudGecko said:


> I know this thread is a year old, but I've been toying around with this exact same idea.  We have a Berkey water filter setup on our counter that seems to always be empty.
> 
> My original thought matched the ideas discussed here regarding use of a float switch.  After considering the same issues mentioned, I'm thinking of using a digital scale to monitor the amount of water in the entire system (top and bottom portions).  A Berkey that's full in the upper tank or bottom tank (or somewhere in between) should have a constant-ish weight.  If the total weight drops below a certain threshold, open a solenoid driven water valve to flow water into the upper tank until the total system weight reaches the "full" level.
> 
> Anyone see any holes in the theory?



Sounds good to me. to the forum.


----------



## frodo (Nov 3, 2015)

ice maker fill valve


----------



## Tom B (May 8, 2021)

I also find our Berkey filter always empty. I thought about this auto-fill possibility then searched the web and found this chat. Cool. I have not done this yet, but my idea was the dual float switches with a 12v solenoid valve. The float switches would be wired in a series circuit to the solenoid load. The fist float switch would be low in the bottom tank. You would wire it as normally closed when float is down. The second float switch would be high in the upper tank above the filters and also wired NC when float is down. When water runs low in the bottom tank the lower float switch closes allowing current to flow opening the solenoid which needs to be NC as well. Your water inlet is high in the upper tank and when the tank fills to the top activating the upper tank float switch it kills the circuit. It takes a good while for the Berkey to drip down, so most likely the upper tank will fill before the lower float switch cuts the power. You could also put in a delay timer. I am using one I got for $30 for my soda ash injection system. You can wire this delay timer into the circuit to only allow the solenoid valve to stay open for a desired time. If your water inlet is at a relatively low GPM you can be assured that that GPM will be consistent even when your water pressure is at its lowest. That way you can time pretty accurately how long it will take to fill the upper tank. All of this equipment is about $100. This could elevate the horror of no water left in Berkey syndrome.


----------



## slownsteady (May 9, 2021)

Sounds pretty good. 

Welcome to the forum.


----------



## Junto (May 9, 2021)

I enjoyed this thread as I also have a Berkey and my wife and I used to have the problem with running out of filtered water.
First, I'll submit that you should consider what Berkey has to offer:  Auto-Fill
I haven't yet gone this route.

In our case, extortion worked for me.  If my wife didn't insure there was water in the top tank when we went to bed, she'd have to wait for her coffee in the morning, since I'm usually the one who makes the coffee.  

Another consideration I don't recall seeing noted is the fact that the top tank inserts into the bottom tank, and the two tanks are sized such that the contents of the top tank will fit into the bottom tank if the bottom tank is empty when the top tank is also empty when filled.  An issue surfaces when you just top-off the top tank.  You may not overflow the bottom tank, but if the level rises to the point where it covers the interface/lip between the two tanks, you no longer have air-behind-water and you won't have flow (or very little).

Good luck.
Rick


----------



## 68bucks (May 9, 2021)

I never heard of these filters. What's the advantage over a pressurized RO system other than the water the RO wastes? It doesn't look like they are cheap.


----------



## Junto (May 9, 2021)

My understanding is that RO systems remove minerals where a Berkey system does not. (Best to confirm that.)


----------



## 68bucks (May 9, 2021)

Junto said:


> My understanding is that RO systems remove minerals where a Berkey system does not. (Best to confirm that.)


Yes an RO will remove desirable minerals. My system has a re-mineralization stage for that.


----------



## Tom B (May 10, 2021)

Junto said:


> I enjoyed this thread as I also have a Berkey and my wife and I used to have the problem with running out of filtered water.
> First, I'll submit that you should consider what Berkey has to offer:  Auto-Fill
> I haven't yet gone this route.
> 
> ...


Junto, the product you are referring to is quite a coincidence. It is sold by Berkey Supply but is actually for ponds and stuff. I called them and they say they get calls all the time about it.


----------



## Junto (May 10, 2021)

Wow, I stand corrected.  Should have looked more closely.  As I drilled a little closer, it wouldn't have worked anyway.  However, my extortion idea works.


----------



## Tom B (May 10, 2021)

I can’t do that with mine. I found a good video of someone who built one….


----------



## Junto (May 10, 2021)

Cool.  Thanks for posting.


----------

