Using Iron Filters Between Well Head and Water Storage Tanks

[Michaelco]

We want to filter iron, manganese from a new well, prior to it entering a couple of 5,000 gallon storage tanks. .
Our Iron levels are .740 mg/l
and Manganese .051 ppm.
There is also a slight sulfur smell (hydrogen sulfide), but figure the filter will be able to deal with that as well.

Water usage:
The well, is set to pump at 10 gpm, and has the heaviest use when we're irrigating our main orchard - we use drip irrigation, which uses ~3000 gallons per irrigation. We have other fruit/nut trees we irrigate which we schedule for a different day. The most we have used across any two days is 5,000 gallons. The house use is negligible compared to the irrigation - less than 50 gallons a day.

We're looking at an Air Over Media type filter whose controller provides an output for controlling the well's submersible pump.
It seems most of the iron filters are typically located on a line that's always under pressure, so there is no problem when the filter goes into a backwash/regen mode.

In our case, the water line heading into the storage tanks will not be under pressure, and there won't be any water flow unless the tanks are low and has turned on the well's submersible pump.

I posted on the Water Softener Forum, received the following caution about using an iron filter with our setup:
“The AIO style filter needs pressure on the tank at all times to contain the air pocket. Sending 10 GPM through an AIO filter would probably pull the air bubble right out so you would want to add a flow restrictor downstream of the filter”. I would think this problem has been solved before - How have others handled this situation?

I was also told the Fleck 5800 SXT filters provide a relay output which would turn on the pump when the filter starts regeneration. In addition, I found Clack makes water treatment valves with relay output, and WaterStore.com filters use Clack valves - I don’t know anything about the quality of Clack valves, nor, for that matter any of the various manufacturers, but it looks like they make a reasonable valve. I’m still waiting for a response, from waterestore.com, confirming their iron filters use the Clack water treatment valves with relay outputs.

Any thoughts on other iron filters to consider? I have looked at other filtering approaches like TripleOs ozone system, but didn’t like the maintenance requirements, and unsure whether a single system would work with two 5k storage tanks connected in series.

Any design ideas on how to incorporate iron filters to avoid any pitfalls?

Thanks,
Michael

 

[Valveman]

Might look at the Sulfur Eliminator as it aerates the water in the well to get rid of iron and sulfur.

 

[Sponsor]

 

[Michaelco]

Might look at the Sulfur Eliminator as it aerates the water in the well to get rid of iron and sulfur.

Would this even work with our system? No water at well head to circulate unless the submersible pump was running. The well output feeds into the storage tanks, when tanks water level is below upper float.

Would it work, without reconfiguring the system with pressure tank, and valve?

 

[Valveman]

Would this even work with our system? No water at well head to circulate unless the submersible pump was running. The well output feeds into the storage tanks, when tanks water level is below upper float.

Would it work, without reconfiguring the system with pressure tank, and valve?

Call the old well driller in Georgia that makes them. He can tell you.

 

[LLigetfa]

An iron filter can be installed inline before the storage tank but then you need to configure it to use pressurized water from the house to backwash it. Best to post in the softener forum where there are experts that know how to do that.

Alternately, you could use a pressure tank and pressure switch on the well pump so that it could be used to backwash. The storage tank would need a solenoid valve or a float valve.

 

[Michaelco]

An iron filter can be installed inline before the storage tank but then you need to configure it to use pressurized water from the house to backwash it. Best to post in the softener forum where there are experts that know how to do that.

Alternately, you could use a pressure tank and pressure switch on the well pump so that it could be used to backwash. The storage tank would need a solenoid valve or a float valve.

I had thought of having a different configuration but wanted to avoid all the extra pieces - could have the well feed into a pressure tank located at the storage tanks, which would be connected to the iron filter. Between the filter and storage tank inlet would be a solenoid valve which would be opened when the upper tank float dropped below and closed when the tank was full. The well pump would be controlled by a pressure switch mounted at the pressure tank - turn pump on when pressure drop below low setpoint, and back on when above upper. This would make it a more typical setup, but more pieces to deal with, and go wrong.

I have a pressurized water line at the tank, so could use it to backwash, and have the filter controller operate a 3 way motorized valve. Normal valve operation would connect the water line from the well to the iron filter, and during regen the iron filter would be connected to the pressurized line. I prefer this idea but hesitate because of the caution I got that the air bubble in the iron filter would get “pushed out“ when the well pump started the 10 gpm flow.
Is that real, and if so, could a flow restrictor (dole valve) keep enough back pressure to prevent that from happening?

 

[LLigetfa]

I prefer this idea but hesitate because of the caution I got that the air bubble in the iron filter would get “pushed out“ when the well pump started the 10 gpm flow.

The iron filter is downflow so the air is always at the top but if there is not a constant pressure, the air "bubble will expand and some of it will get expelled.

You could use an iron filter that relies on a separate precipitation (HP) tank and a micronizer to inject air rather than just gulp air during the backwash. If the HP tank has a side port, it would not need an AVC to control the volume of air in the tank. Feed the water in the top port and out the side port.

 

[Michaelco]

The iron filter is downflow so the air is always at the top but if there is not a constant pressure, the air "bubble will expand and some of it will get expelled.

You could use an iron filter that relies on a separate precipitation (HP) tank and a micronizer to inject air rather than just gulp air during the backwash. If the HP tank has a side port, it would not need an AVC to control the volume of air in the tank. Feed the water in the top port and out the side port..

Thanks for the explanation on why you lose the air bubble. Could be interesting/promising - what are the downsides of this approach? Cost, reliability, maintenance, …??
There’d be pressure variation, even using the pressure tank approach I had mentioned before.
Any suggestions on manufacturer/models?

 

[LLigetfa]

what are the downsides of this approach?

The downside is that the micronizer is a flow restrictor so it limits the GPM. How much, depends on the well and pump metrics. Limiting GPM is generally not a problem if just refilling a storage tank just so long as there is enough GPM for the backwash. That depends on the iron filter media and tank diameter. A micronizer's downside is felt more on the house supply system which it is not in your case.

A micronizer and downstream piping is a high maintenance item due to the precipitated iron build up. Keep a spare micronizer with unions for a fast swap and oversize the pipe so it takes longer to build up. Use long sweeps or multiple 45 degree elbows so the iron doesn't build up in the elbows and to make it easier to flush it out when needed. A few unions in the line makes it easier to clean out the pipes.

Maybe @ditttohead can advise on models that meet California laws.

 

[Bannerman]

Maybe @ditttohead can advise on models that meet California laws.

Ditttohead does not usually monitor the Pumps and Tanks forum unless specifically requested.

 

[LLigetfa]

Ditttohead does not usually monitor the Pumps and Tanks forum unless specifically requested.

Yes I know which is why I suggested this be posted in the softener forum. I think however that by my using @mentions, that he should get an alert to this thread.

 

[Valveman]

Sorry, I will move it now.

 

[Michaelco]

The downside is that the micronizer is a flow restrictor so it limits the GPM. How much, depends on the well and pump metrics. Limiting GPM is generally not a problem if just refilling a storage tank just so long as there is enough GPM for the backwash. That depends on the iron filter media and tank diameter. A micronizer's downside is felt more on the house supply system which it is not in your case.

A micronizer and downstream piping is a high maintenance item due to the precipitated iron build up. Keep a spare micronizer with unions for a fast swap and oversize the pipe so it takes longer to build up. Use long sweeps or multiple 45 degree elbows so the iron doesn't build up in the elbows and to make it easier to flush it out when needed. A few unions in the line makes it easier to clean out the pipes.

Maybe @ditttohead can advise on models that meet California laws.

Thanks for the information - I do want to maximize the flow rate - Just in general, pump running with full capacity means less pumping time, and quicker storage tank recovery. I don't know the minimum GPM needed for the filter, but even a 5 GPM would satisfy our current water usage needs.

Also, for the time being, the well produces fine, with little drawdown, but with a couple more years of drought, the picture could drastically change - so we could fall a lot further down on the pump capacity curve.
I assume calculating the GPM with the micronizer in the picture would factor in the pressure drop across the micronizer venturi along with the 1 1/4" pvc line (350') from the well head - is this accurate. I have no feel for the drop across an micronizer, nor sure I understand exactly how they work - probably don't need to know, in order to use - I understand the venturi effect, but don't have a feel for how the air get's disbursed in the water - seems having more small bubbles would be more effective than larger air bubbles.

I'm thinking having any micronizer example would be useful to give a ballpark on pressure drop, but more importantly the size of the units.

I'm thinking, having the micronizer located as close to the filter would be beneficial, as less pipe would be affected by buildup.
I like the idea of having a spare, for quick changeout. The other thing I haven't brought up, but might be an issue is my plan to have the filter located in a space between the two tanks. We're fairly mild here, but have some winter temps that can drop to 25℉. In general, I go with larger pipe diameter than needed to reduce vulnerability to pipe damage - but, don't know if the micronizer will be more vulnerable to a freeze, nor whether the water mass from the storage tanks will be enough to protect smaller volumes that are in a venturi.

Thanks again for your help.

 

[Michaelco]

Looking at a system which inject ozone prior to an iron filter. There are a couple of things that are a bit of a challenge to figure out, so could use some help. Have seen half life numbers for ozone anywhere from a few minutes to 30 minutes, and don’t know if I have to worry about the corrosive effects on the iron filter, tanks, pressurizing pump and pressure tanks. I believe the storage tanks are made of polyethylene. The two 5k gallon storage tanks are connected together at the bottom, and the water inlet is at the top.

Our heaviest single use is about 3k gallons when we irrigate (drip) the orchard over a 6 hour period. The tank water level shouldn’t drop, as the new well should be able to keep up with the usage rate. Don’t know if this is true, but I would think it would be unlikely for much of the ozonated water to make it to the second tank - as the ozone would tend to rise to the top of the first tank, and the second tank gets water from the bottom connection. Does this seem like a reasonable assumption?

The pressurizer is located 150’ from the storage tanks, and connected via 1 1/4” water line - roughly holding 10 gallons. Pressurizer cycles on every 10 minutes when the orchard is being irrigated, and I plan to measure the volume of water during each cycle (40/60). I’m sure it’s more than the 10 gallons, but don’t know how much of the water from the storage tank makes it’s way to the pressurizer and pressure tanks. The pressure tanks (Well Xtrol) have polypropylene liner, and butyl diaphragm. We’re using a StaRite HMS-1F pressurizer pump - have an email into them to see how they are affected by ozone. Unless we over do it on ozone, I wouldn’t think this would be an issue, but I don’t have any experience with this. We have unions in a number of places - don’t know the o-ring material, nor whether it’s worth researching down to this level.

I also don’t know if all of the iron filters (and valves) are built to handle the ozone. Looking for suggestions on equipment that would do the job and hold up.

I figure our ozone needs are fairly small - less than 2 grams/hour - that is, if I did the calls correctly (with the .740 mg/l Iron, .051 ppmManganese and slight sulfur smell). Ph is 8.4

Any help would be appreciated

 

[Reach4]

I would think that the drip irrigation on the orchard would be best with the iron still in the water. Do you have contrary info? I am not a pro.

 

[Michaelco]

I would think that the drip irrigation on the orchard would be best with the iron still in the water. Do you have contrary info? I am not a pro.

Biggest issue at the level iron we have is clogging of drip emitters. Have read above .1 mg/L can cause the issue. Also, the ag report says staying below .300 mg/L is optimum. Our soil has a high iron content as well, but I don’t know it’s bioavailability. Most likely, the plants would be fine with the combined level from the water and soil - that is, if the drippers don’t plug up :~).