Victory (finally!) over iron

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diggity

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I'm sure I have long ago bored the poor souls who were unfortunate enough to stumble on any of my previous posts here on this forum as I tried to fix my water system over the past few months, and for that I apologize. But I have some happy news for once! And I can't resist posting one more time, partly to get it off my chest and partly for the benefit of anybody else who is unfortunate enough to have water as horrible as ours.

To recap, we have over 20 ppm of iron, TDS around 1400 or so, pH around 5.25, and 50 grains of hardness. But despite all this nastiness, and skipping to the good news, today I tested the iron at the upstairs faucets, and the level was... zero! For the first time in the 13 years we have owned this house, our water is free of iron! I feel like dancing, but me dancing is a pathetic sight to see, so I'll just sit here an smile instead. :)

Apparently the key was that our water is so bad that it doesn't conform to the typical advice, which is to treat iron before softening. Been there, done that, and it just didn't work for us. The paradigm that works for us is this: If the softener can remove 80% or 90% of the iron by itself, then let it. And remove whatever remains via oxidation and sediment filtration. I doubt this tactic would work if the raw water had ferric iron and/or high pH. But in our case, our water is really acidic and all the iron is ferrous - both conditions which softeners actually prefer. So fine, Mr. Softener, do your thing. Knock that iron down from 20+ ppm to 3 or 4. We'll clean up the rest downstream.

I tried to remove the iron before the softener... I really did. But I didn't fully appreciate what I was up against. If the peroxide feed rate was too low, it didn't oxidize all the iron. If the feed rate was ridiculously high I could oxidize all the iron, but then struggle to remove it.

So after a couple months of trying to oxidize all that iron before the softener, I finally re-plumbed everything over the course of the past two weekends. Here's how bad it was: There was rust literally everywhere - all through the contact tank, piping, everywhere. My contact tank is just an old empty filter body... just a flow through head and a riser tube. When I took it apart it was of course filled with orange water. The distributor basket was just about plugged, and the riser tube had so much rust in it that I had to take it outside and flush it with the hose. When I did so, it looked like the tube was pooping out a 2 foot turd of pure rust. Sorry for the visual. It was pretty gross.

The first weekend I plumbed the softener first in line. No injection of soda ash or peroxide. When I turned the water back on it was REALLY bad. It blew chunks for a couple days and then gradually cleared up. Still though, by the end of the week, there was over 5 ppm of iron at the faucets, despite the fact that there was only 3-4 ppm coming straight out of the softener. How could that be? I double checked it to make sure I wasn't seeing things. I think what was happening was that, because I was not correcting the pH during that time, the very low pH water was actually scouring rust off the pipes. Converting it back to ferrous and delivering it right to our sinks and toilets. Yuck.

The second weekend I plumbed the injectors and contact tank back in, and voila! The water quality improved dramatically. Iron is now zero, the taste and smell are fine, pH is around 7, and the TDS even drifted down a bit, from around 1400 to around 1200. (TDS is still high, I know, but we have an RO at the kitchen sink for drinking water)

So here is the final configuration:

Well --> 40 gallon pressure tank --> Dual softeners --> Peroxide injection --> Soda ash injection --> Contact tank --> 4 gallon pressure tank --> Katalox Light filter --> Sediment filter (Chemsorb)

Picture can be seen here: https://flic.kr/p/EB6aiD

In case you're wondering as to the purpose of the little 4 gallon pressure tank, it is to absorb any additional pressure created by the Stenner pumps if they happen to come on during a time when there is no demand for water in the house. For example, when the softeners backwash. The Stenners are wired into the switch on the primary 40 gallon PT, which is BEFORE the softeners, but the injection points are AFTER the softeners. So when the softeners backwash and the well pump kicks on, the Stenners may create excessive pressure in the lines because the injection points are after the primary PT's check valve. So the little PT absorbs any extra pressure in the lines. The Stenners only inject an ounce or two every time the well pump runs, so we're not talking about a major amount of water anyway. But still, the mini PT seemed like a good precaution.

I had thought about buying an atmospheric storage tank and air pump, because it seems to me that good old air does a marvelous job of oxidizing iron and just improving overall water quality. But I'd need a big tank - probably at least 150 gallons, and those are expensive. And shipping is very expensive too. And I'd need a shallow well pump for re-pressurization. And I'd need to find an appropriate float valve - one that could handle typical household pressure and flow. Seems most float valves are built for aquariums. Anyway, when the peroxide Stenner pump eventually dies I'll revisit the issue. For now, peroxide seems to be good enough. I'm diluting 7% peroxide (NeutraSul) by half and the pump is at setting 4, which means I'll go through about 2 gallons of peroxide per month. Not too bad.

I still have to tweak the injection flow rates and backwash frequencies, but I finally feel like I'm on the right track. Thanks again to all of you who offered advice during this odyssey!
 

Reach4

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Success is good. Very innovative. Your thought that the acid helps the resin handle the iron is appealing in that they add acid to salt to make it.

The concern is resin life I think. You will monitor the residual hardness I am sure. Keep us tuned in.
 

diggity

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Yes, I'll definitely be monitoring the residual hardness. So far so good - although the resin is 13 years old, it still seems to be doing its job, as we're only getting 1 grain or less at the sinks. The only downside I can think of in this configuration is that we'll probably use a little bit more salt, since the KL and sediment filters will demand water from the softeners whenever they backwash. But currently they are set to 3 day and 4 day cycles respectively, so it shouldn't be too bad.
 

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How often is/are the softener(s) regenerating (not sure how to look a the two-tank system in this case)? Usually when softeners are used for iron removal, setting the DO lower is recommended. Your high-acid softening technique is blazing new ground as far as I know.
 

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Somewhat fortunately, the Kinetico softeners regenerate based on the amount of gallons, not time of day. I say fortunately because that means they are most often regenerating during the day, when people are around using water periodically (I'm still a tiny bit concerned about the extra pressure in the pipes from the Stenner pumps, even with my little 4 gallon PT to absorb it, so knowing that we are usually opening faucets, taking showers, flushing toilets, etc. and thus relieving the extra pressure is somewhat comforting). What does DO stand for?
 

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(I'm still a tiny bit concerned about the extra pressure in the pipes from the Stenner pumps, even with my little 4 gallon PT to absorb it
I expect most of the time, adding pressure downstream makes its way to the main pressure tank. I expect that any total blockage of that path, if any, is short.

What does DO stand for?
Day Override in Fleck programming.

Gary Slusser is a top proponent of using a softener for removing significant iron as well as hardness. In http://www.qualitywaterassociates.com/sizing.php he says
If you have 2.0 ppm or more of iron, you may want to regenerate every 3-4 days. If so divide the numbers you just produced by 2. Round each up/down, they are your salt dose and capacity figures. Then you will Calender Override the control at day 4. Depending on your iron content, you may want to consider a softener with a Turbulator distributor tube and/or SST-60 resin and to use a resin cleaner.​
I infer that Calendar Override is the equivalent term used by Clack.
 

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The Kinetico softener settings are programmed by a disk located in the head. To change the capacity setting would require replacing the disk.

My contact tank is just an old empty filter body... just a flow through head and a riser tube.
Since ferrous iron will oxidize to ferric iron from the peroxide injection point forward, iron will precipitate within the contact tank. As a filter tank does not have a bottom port to discharge the iron deposits & sediment, it cannot be easily cleaned-out and will continue to fill with ferric iron.

the Stenners may create excessive pressure in the lines because the injection points are after the primary PT's check valve.
Did you relocate the check valve to downstream of your primary pressure tank? If so, what is preventing the pressurized water in the primary tank from flowing back into the well?

While you have a concern with the injection fluids having nowhere to go without the small expansion tank, a larger concern is thermal expansion when cold water is heated in the water heater. As liquids cannot be compressed, the expanded water must go somewhere. If the expansion volume can't flow back to the main pressure tank or to an expansion tank, then the water heater pressure relief valve will end-up being the relief point.

Edited to add: Gary's softener sizing page also states: If over 5 ppm - you need an iron filter.
 
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If the expansion volume can't flow back to the main pressure tank or to an expansion tank, then the water heater pressure relief valve will end-up being the relief point.
It seems to me that people with a main pressure tank almost never need a separate thermal expansion tank for thermal expansion. And if there is a short interval where water gets blocked, diggity has that potential problem solved by having that extra tank-- even if a Stenner pump turns on.
 

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It seems to me that people with a main pressure tank almost never need a separate thermal expansion tank for thermal expansion.
Agree'd, unless a backflow prevention device (ie: check valve) is located between the pressure tank and the water heater. Looking at Diggity's part sentence I quoted, seems to imply that is the situation.

The expansion tank was intended to absorb the volume pumped by the two Stenner pumps but Diggity didn't mention thermal expansion.
 

diggity

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Bannerman, no, I did not relocate the check valve. Never thought of that, actually! And there is no other check valve anywhere in the system, besides the one on the primary pressure tank. Regarding ferric iron accumulating at the bottom of the contact tank, I'm sure you're right - it will. I pulled the distributor basket off the riser tube, so it's basically just an open pipe now. And the direction of flow is down through the body of the tank and then up through the riser tube. So hopefully most of the rust precipitates will go up the riser tube and out for filtering in the KL/sediment filters. But I guess the only way I'll know for sure will be to check it, which I will do in a few weeks.

Anyway, I think the water heater should be OK - it is a Stiebel Eltron Accelera 300 (which by the way has been totally awesome for us and saves so much in energy costs, but that's a different topic!). Anyway, it has its own little expansion tank.
 

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Agree'd, unless a backflow prevention device (ie: check valve) is located between the pressure tank and the water heater. Looking at Diggity's part sentence I quoted, seems to imply that is the situation.
Good catch. I had missed the check valve part. Those who use a topside checkvalve in a submersible pump system usually have that before the pressure tank. I think the case for not having a topside check valve is good, although often there is no problem for those who do so.
Bannerman, no, I did not relocate the check valve. Never thought of that, actually! And there is no other check valve anywhere in the system, besides the one on the primary pressure tank.
There is almost surely a check valve at the submersible pump. Usually it is best to have that be the only one. That keeps the pipes to the well pressurized, even in the face of a slight leak.
Did you relocate the check valve to downstream of your primary pressure tank? If so, what is preventing the pressurized water in the primary tank from flowing back into the well?
The check valve at the pump. To the extent that a bit of water might flow back toward the pump, that is good. That water would compensate for a small leak in the piping or pitless.
 

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As you stated: "the Stenners may create excessive pressure in the lines because the injection points are after the primary PT's check valve.", that
implied the CV was located after the PT.

With no check valve after the PT, then there should be no concern over either thermal expansion or the additional liquid volume added by the Stenner pumps. Neither the softener nor filter valves prevent backwards flow so the expansion tank would then be unnecessary although there is no harm in having it

A contact tank with a proper bottom drain port would permit flushing away the solid ferric iron deposits directly without unnecessarily exposing the downstream filters to all that solids load.
 

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Neither the softener nor filter valves prevent backwards flow so the expansion tank would then be unnecessary although there is no harm in having it
I had been wondering if there might be a transient interval where this path would be blocked. I guess not, because the designers don't want to shut off the flow of water to the output during regen -- even for a brief interval while valves are moving to establish bypass during the regen.
 

diggity

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Is that where the check valve is? On the well pump? (slaps hand to forehead) I'm such a dummy! Now that you mention it, somewhere in the back of my head I knew that, but for some reason I was thinking there was a check valve on the T assembly at the PT.

Guess I didn't need that 4 gallon PT - I should have checked with you guys first!
 

diggity

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Actually, nevermind my last message (and I'll try to remove the handprint from my forehead). There must be a check valve on the T fitting on the main PT. There is a spigot on the pipe right after it enters the house. I can only get water from that spigot when the well pump is actually running. If there were no check valve, then there would always be water at that spigot because it would flow backward from the PT.
 

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Is that where the check valve is? On the well pump? (slaps hand to forehead) I'm such a dummy! Now that you mention it, somewhere in the back of my head I knew that, but for some reason I was thinking there was a check valve on the T assembly at the PT.

Guess I didn't need that 4 gallon PT - I should have checked with you guys first!
In some areas, a topside check valve is common or maybe even required. In those places, that checkvalve would be on the upstream side of the pressure tank.
https://terrylove.com/forums/index.php?threads/well-pump-and-tank-questions.64823/page-2#post-480596 is one of the threads that got into the topside check valve discussion.
 
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