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13. Acid Well Water: The Simple Way to Neutralize Acidic Well Water & End Copper Corrosion Problems

no salt water softenersDid you know that rainwater is slightly acidic, and in some cases can be very acidic?  This can cause acidic groundwater and might cause your well water to be corrosive to plumbing, fixture, and appliances.

Common causes for acidic well water are from acid rainfall due to atmospheric carbon dioxide and other airborne pollutants, and in some cases, runoff from mines.

Pure water has a pH of 7.0 (neutral); however, natural, unpolluted rainwater has a pH of about 5.6 (acidic). The acidity of rainwater comes from the natural presence of three substances (Carbon dioxide, nitrogen oxide and sulfur dioxide) CO2, NO, and SO2.   (CO2) is present in the greatest concentration and therefore contributes the most to the natural acidity of rainwater. As CO2 levels rise, acid rain might be increasing as well.

Some items I talk about in this episode are the source of acid water, how it is formed, and what you can do about it.

How to Neutralize Acidic Well Water?

  1. Test your well water first, for at least: pH, alkalinity, hardness, total dissolved solids
  2. Use a calcite neutralizer to eliminate the acid pH… OR
  3. Use a blend of calcite and magnesium oxide (Corosex or Flomag brands etc) for very low pH
  4. Use a backwash type neutralizer OR an upflow neutralizer, depending on your application and water
  5. Consider a soda ash injection system if your pH is 5 or below, and/or your water is high in calcium

Have a question? Please don’t hesitate to email me at .

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Episode 13: Acid Well Water: The Simples Way to Neutralize Acidic Well Water & End Copper Corrosion Problems

Calcite Neutralizer Filter System

Hello, hey, thanks so much for tuning in again to the Clean Water Made Easy Podcast. Gerry Bulfin here. As you may know, I’m a Water Treatment Contractor and WQA-Certified Master Water Specialist. I hope you’re having a nice day wherever you’re listening or however you’re listening.

In this series of podcasts, I’ve been giving useful, easy-to-follow tips and information all about well water, well water treatment systems, and how to improve the quality of your well water.

Today’s episode is all about acid well water. Very common. Will also talk about acid rain if you’re using rainwater, and spring water, all of which can be acidic in private water systems one of the most common causes of pipe and fixtures corrosion is from low pH which means acidic. It’s a pH of less than 7.  pH is just a scale. You can think about it as between 1 and 14;  7 is neutral.

I’m also going to give an overview of the different kinds of systems used to treat low pH.  Actually, it’s very easy to treat, which is fortunate. How copper corrosion occurs from acid water; how to slow down and how to eliminate those blue stains which is very common-the blue stains from copper corrosion.

Download Free Guide

We also have a really good guide, a little eBook, 21 pages, called How to Treat Acid Well Water. It has pictures, diagrams, very easy to follow. If you don’t want to take a lot of notes when you’re listening to this, and you just want to get the guide, that could be a good way to go. I posted a link in the show notes if you want to get your free copy.

You can get it by going to or if you can’t find it just email me at and I’ll get to you your free copy.

So like I said in this episode we’re going to go over copper corrosion, how acid water occurs, how to slow it down, eliminate copper corrosion and get rid of blue stains, where to go over the main systems used to treat low pH on residential groundwater and those are: calcite neutralizers, calcite Corosex, or Flowmag,  blend neutralizers, upflow neutralizers, and soda ash systems. I’ll go over briefly what the differences are.

What causes acid water anyway? Well, common causes for acidic water are from rain, acid rainfall. Mostly due to atmospheric carbon dioxide, the CO2 levels are increasing, we’re seeing more and more of it generally but it comes from other airborne pollutants as well –coal burning, other fossil fuels, vehicles, pollution, and then run-offs from mines is another way it can happen.

But mostly it’s from the rain. So pure water has a pH of 7 which is neutral. However, natural unpolluted rainwater actually has a pH of 5.6. So it’s naturally a little acidic.  The acidity of rainwater comes from the natural presence of carbon dioxide, in some cases nitric oxide, and some sulfur dioxide from coal burning.

CO2 is present in the greatest concentration in air, this is from the studies that I’ve been able to gather and therefore contributes the most to the natural acidity of rainwater. It’s interesting to think about it. The rain comes down, eventually gets into the groundwater, that’s where we have our wells, you pull out the water from. If you’re in an area which is very common the natural rock or fractured rock where the groundwater is in limestone, or maybe sand, or some other mineral, it has a huge effect on whether that water would be acidic when you pull it out.

For instance, if you’re in an area where the groundwater is sitting in limestone, well it’s getting neutralized right there. Acidic water dissolves magnesium as the water you have hard water but no longer acidic corrosive water. But if you’re in an area where it’s granite, or sand, or some other mineral, isn’t going to contribute a buffer, pH buffering into the water, then the water comes out of the ground often really good quality but it’s acidic. So we see this very commonly.

Many thousands of customers actually got neutralizers and neutralize their acidic water over many years we’ve been at this.  Lots of times the folks have really great water. In other words, it’s low in minerals, low in salt, but fortunately because it’s coming from the ground, the water is just really acidic. What goes into the house if they have copper pipes, they make blue stains, eventually, we get pinhole leaks, corrosion, water heaters are ruined, and so. It’s, fortunately, very easy to fix and that’s what we talk about next.

How does it happen? What is corrosion? How does copper corrosion happen? Well, Corrosion is actually very complicated but you can think of it this way: It’s a natural process involved in a chemical, or electrical degrading the metals in contact with water.

So if you see acid water, signs will be like blue staining, pinhole leaks. You might see rusting too. Like for instance, there are some homes that still have some galvanized pipe in them. Eventually, people are getting rid of that and going to copper. Copper packs a pipe, but a lot of times even if they re-pipe their house you would still have a little pipe nibble towards the section of the pipe, maybe it’s near the shower, maybe it’s going into the water heater.

This acidic water is eating that out and you’re getting rust. And you wonder why do I have rusty water, well my well doesn’t have rust in it.  So acidic water with pH in a range of less than 7 is more corrosive to metals than alkaline water. That’s the simplest way to look at it. So you can have your groundwater could be acidic but your rainwater, if you’re using rainwater. That can be acidic. It is acidic and also spring water can be acidic as well.

So basically, the acid water is just low in this natural buffering calcium minerals.

What to do? Well, fortunately, it’s very easy to fix. What you can do is, the common systems we use to treat low pH are calcite neutralizers.  Calcite is this white mineral which looks like white sand, and it’s  just natural pure calcium carbonate. There are different grades of it, different types. The type that we recommend is this high purity kind. Just add some natural calcium into the water. That works if your pH is 6 and say 6.9. The regular which is the most common pH we run into with some customers.

Sometimes the pH is less than 6, between 5 and 6. Then we’ll use a blend of calcite and calcium carbonate and magnesium oxide. For instance, there are different brands. Some people are for corosex, or which is a Glock brand or there could be Flowmag, which is a brand we use. It’s a high purity, natural magnesium oxide. You got a little bit of that. Mostly it’s calcite and a little bit of corosex. Calcite neutralizers and calcite corosex neutralizers are backwashing systems, backwash out. Then there’s upflow neutralizers and soda ash systems. Those are the main types. We’ll talk about each one briefly and how and what’s the best one to get clear water.

The first thing to do is to figure out what your water chemistry is.  Do a simple water test and you want to know in the minimum: What the pH of the water is, again that’s a scale from 1 to 14. Lemon juice has a pH of 2 or 3. In other words, it’s a little acidic or low pH.  Ash soda is acidic, that is low pH and then it’s alkaline or alkaline substitute like baking soda, that type of thing.

So you want to know what the pH of the water is, what the hardness is, what the total dissolved solids are, and the alkalinity.

If you have those at least a minimum of those 4, get your water taken to a lab and have it tested. Or you can test it yourself. It’s often a good idea to at least do one pH test on site because the pH can rise.

For instance, pick a sample of your water, you want it to get tested, say you filled the sample three quarters away, then you take it to the lab, they let it sit around for a day, then they get around to test it, the pH will be a little bit higher because one of the causes of pH is dissolved carbon dioxide in the water. The dissolved carbon dioxide creates carbonic acid. If you were to spray this water in the tank, let it sit around, or put it in the glass, it will naturally rise in pH.  So it’s very important to do at least one pH test at the site.  It’s easy to do and you can also have a test by a lab. Those are the main things you want your water to get tested for.

You can take that and you will know what kind of you’re dealing with as far as what kind neutralizer will be best for your system.

First, let’s talk about the Calcite and Corosex blend neutralizers. This is one of the most convenient ways to raise pH. A picture of these is in the guide. It’s like a tank for a typical home, usually 3 to 5 feet tall and 10-12 inches wide. These tanks are filled two thirds full of calcite.

They have an automatic backwash control valve so when the water flows in, it flows down to the calcite media. It’s instantly neutralized. The acid water goes in, coming out it’s nice, neutral water.  For some folks, they say that after a week or 2 the blue stains stopped. They can have a pretty strong and immediate effect of slowing down the corrosion in the pipes.

Neutralize Acidic Well Water

We usually recommend a backwash neutralizer to neutralize acidic well water. There’s some controversy, people have different opinions about it but essentially, if you have a backwash type what that means is once or twice a week it’ll turn on in the middle of the night and at natural water pressure, will backwash and lift the media up inside and flush the waste water out to drain and it’ll flush out any accumulated sediment or rust that’s trapped in the media. It acts like a filter for your home, too.  It gets rid of the little sediment. Calcite is pretty fine, can trap sediment.

More importantly is, when it’s doing that, the minerals are grinding against each other a little bit and it’s reclassifying the bad. You’re getting a way for the mineral to get stirred up and dissolve a lot better over time. We’ll talk about upflow neutralizers next, but that’s the main difference.

Re upflow neutralizers they flow up through the media instead of down around. They act as filters filtering most up through the calcite but there’s no backwash to them. That’s one way to go, too.  It’s a simpler system and cheaper.  But water can channel around the media. They don’t act as a filter.  We found, for the extra trouble involved of hooking the thing up, you’ll need a backwash aligned to your drain.

The water’s not toxic, you can run it around outside for free. Anyway, there are different ways to deal with the backwash. Nothing toxic in it, just your well water. You can flush it into the drain or septic tank.

how to neutralize acidic well waterIn any case, you have the backwash filter plus the upflow. We generally found the backwash to work better. It’s worth a little bit of extra money in time.  Over time, the media just dissolves naturally.  Once a year, you can unscrew the low plug up on the tank,  unscrew the plug and all you have to do is pour more calcite in. You can keep this neutralizer about two thirds full of this natural white mineral that will eliminate the pH problem.

So how does it work?  Well basically as the water flows through it slowly dissolves some calcium and magnesium and then that’s what does it – erase pH by adding calcium magnesium. Usually, it depends on how hard the water is. One common question we get is, “Hey will the neutralizer make my water hard? I like my water the way it is now.”

It does increase the hardness of your water but it’s not by that much. Usually fo, ks have naturally soft water.  A lot of times acidic water is naturally soft water too.  When in the ground there’s no hardness of minerals less hardness minerals to dissolve into the water.  But the hardness levels are pretty low. It flows through there, it’s harder, but it’s not that bad.

Speaking of how hard the water is, we usually recommend to folks: “Just try the neutralizer first. Try it for several months. It’s better anyway because it will run the hard water through the pipes and stop the corrosion quicker and later, if you want, you can always put a water softener in to remove calcium.

The water softeners do not lower pH and do not make water more corrosive. So it won’t hurt the corrosion of the pipes at that point. So essentially the size of the systems, have different sizes that these things come in, usually all based on how fast the water is flowing through the pipes.

There are only a few different sizes for most common-sized homes- 1 or 2 bathrooms, 3 bathrooms. For big homes, there’s a couple of different sizes. The ideal is it’s nice to get a size where you can go at least a year without adding any more mineral to it.

We usually recommend a 1½ cubic foot or 2 cubic foot of the calcite mineral in tank. You can see the sizing guide, it’s very easy to size them if you get in the backwash type. The other that’s important is to know how many gallons per minute, I talk about this in the other episodes. It’s important to know how many gallons per minute is my well pump is putting out.

Say, it flows 10 gallons in one minute, that’s a 10-gallon per minute. If you have 4 gallons per minute, in a low-producing well or for whatever reason it’s producing low flow rate, you wouldn’t want a joint neutralizer because it couldn’t backwash it at the right rate. So you want to get a size of the neutralizer that will backwash at the right rate.

A pretty big one, one and a half cubic foot, they can get by, with say,  7 gallons per minute per backwash. You can look at the table too and see the different flow rate that is required for the backwash types.

Now we’re going to talk about upflow neutralizers.  Like I said the water flows at the bottom from the top and you don’t have to be so concerned about the backwash rate because there are a few issues to it. One of them is when you add more mineral to it, you got to be really careful to flush that thing really good.  It’s get it one time. When you first add it, really flush it, so when you open up the pipe put up the hose bib or valve downstream of the neutralizer flush that good.  When you first start that up, in this case, it is an upflow the water flowing comes out sort of milky white. What can happen is, if you don’t flush it correctly then the media can partially solidify.  This cuts back on your flow rate and can actually cause pressure and flow problems.

So if you’re getting the backwash type it’s truly convenient because when you first put in the service, it backwashes, cleans it up, you’re and good to go. With neutralizers, you got to be a little careful with the neutralizer. Be careful that you really flush that thing really well.

So both backwash neutralizers and upflow neutralizers the standard calcite ones work in the range between 5 and 6.9 so if your pH is 7 of course you don’t need a neutralizer. If your pH is 6.9 depending on whether you’re getting copper corrosion, you might not need one either.   If your pH is 6 and 6.9 we recommend a standard calcite kind, a 100% calcite. When the pH gets below that, between 5 and 6, then you need to use a blend of calcite and magnesium oxide which is another natural mineral that adds magnesium into water like I said get sold into different brands.

Okay. That’s basically the 2 types of neutralizers. For most people, neutralizers is the best way to go. It’s very easy. You don’t have to mess with it every month. There’s no chemicals running, you can’t set it and forget it because if you do that, a couple of years go by and all of a sudden the tank is empty and your blue stains will come back. We actually heard that a bunch of times every year. Folks say: “You know I have a neutralizer in, working great, a couple of years went by, now I get the blue stains again.”

We come to find out the tank is empty.  It’s best to check it every 6 months to a year and just make sure it’s two thirds full.

There are some cases when neutralizers don’t work well.  That’s why I’m going to talk about the next one which is soda ash.  Soda ash has done really well too. That is his bet. If your pH is less than 5, say 4.5, then you got to add a lot of magnesium oxide because calcite doesn’t work that well that low pH. You got to use a lot of magnesium oxide to get it to work because your water is then hard.

So there’s  a lot of hardness to water. The other thing is, it doesn’t really work that well, we found.

In the beginning, the pH is high and then after a while, it drops or use  a lot of water during the day. You can get a bleed through where water, so generally pH is the last  5 we recommend sodas ash feeder. Soda ash is sodium carbonate, a food grade sodium carbonate. Sodium bicarbonate is baking soda, pretty much like baking soda.  It looks like baking soda but it’s a special potable water grade. It’s certified for drinking water – type of chemical.  It’s a powder and basically, you mix it up with warm water and pour it into a solution tank which might be 13-15 gallons in size.

It has on top of it or somewhere nearby a small pump that pumps a tiny bit of this soda ash solution into your pipe whenever the well water runs. The simplest way to set them up is when your well pump turns on, you have the metering pump from the soda ash turn on and it injects usually 1 to 200 parts per million.

If you listened to the episode on Chlorination and Peroxide, usually injected to the 10 parts per million chlorine or peroxide, and soda ash, you need a lot more. You can dissolve as much as you can into the water and there are tables and charts on how to do it, very simple. For that, you’ll need 100 to 200 parts per million or a lot more.  You inject a lot of the solution into the water in order to get pH to rise.  It works really well and the thing about it is that it works well and is very easy to adjust.

So with the calcite neutralizer, basically you get what it’ll do. You can’t really get which the pH means kind of on the size of the tank with calcite pretty you will get this pH most of the time and that is between 7 & 8 or a little bit.  With the soda ash feeder, because you’re injecting it into a pipe where the water is flowing at the same rate all the time.

For instance, the injection point is between the well and pressure tank. For most single speed well pumps then that water is flowing at pretty much the same rate.

Check the soda ash there then you can really dial it in.  what you can do is for now and so you can say, “okay I got my pH at 7.  You can adjust it the or more I want to get my pH at 7 or 8.  Then it’s easy to test it with a pH meter or a simple reagent where you drop a little reagent chemical into a test tube. It’s a test that you can do yourself at your site very quickly.

So the soda ash systems that we recommend if your pH is less than 5, or in some cases if it has a very high flow rate  say a farm or a business where they might have a 40-50 gallons a minute, then you have to get a giant calcite neutralizer might be a little hard to deal with annually. We have some folks using 10 and 15 feet calcite neutralizers on office buildings like 4,5, 10-cubic feet ones, if they didn’t want soda ash for some reason.  We use neutralizers on oil rigs, ships, a bunch of different ships, the need to add a better calcite when they purify water for drinking.

Generally, soda ash works well if you have high flow rate, if you have 40-50 gallons per minute you do have to add soda ash frequently. That’s the downside. Too many downsides to soda ash. One is, the solution you may have to check it out every 6 months and add more solution to it.

The other thing is, it’s sodium carbonate so you’re injecting sodium into the water.  That’s the other downside to it.  A lot of people don’t care. Think about it, recommended sodium guideline, 2000 mg per day. If you put 100 mg in one liter, then, when you drink 1 liter or 1 quart, you’re getting an extra 100 mg. of sodium in your diet. If you’re on sodium restrictive diet, that could be a concern.

It doesn’t affect the taste much, we’ve never had many people complain about the taste of the soda ash. It’s very tiny amount. That’s the 2 main things.

Similar but might cost a little more but if your pH is less than 5 you don’t really have much choice.  Do you want to do it correctly? We recommend soda ash.

Okay. So the soda ash liters work well, and the calcite neutralizers work really well,  it’s just a matter of figuring out what you’ll going to do and type you’re going to get.

Whatever kind you get, if you’re dealing with copper corrosion and the best thing to do is put your system in and then monitor the copper levels. Very easy to do and very cheap around the water and copper levels will drop. There are test strips for copper.  You can start to run the water and the copper levels drop overnight.

But if you left the water sit overnight and you take the first glass of water, you get the high levels of water.  It’s a good idea to monitor it. Make sure it’s going down.  It’s not a guarantee that just because you neutralize pH in water that your copper corrosion issues will be completely eliminated.  But generally, it does. I think that 90% of the time, it solves the problem right off.  But still good to know we recommend so folks check their copper levels periodically. Make sure there’s no copper in the water and also check the pH.  Make sure the pH is fairly neutral if you get a neutral when the mineral levels drop add more of the calcite mineral to it.

Very easy to do it yourself, and of course, you can also hire a local water treatment guy will do it very common. They’ll come out calcite for you pretty easy to do as far as maintenance and quality controls, those are the things we recommend.

In this episode, we went over where acid well water comes from,  how it occurs,  calcite neutralizers,  calcite corosex, blend neutralizers,  when to get an upflow, versus a regular backwash downflow,  blend neutralizers,  and when to get a soda ash system.

I didn’t go a lot into copper corrosion as there are some cases where you have a copper corrosion and your water is not acidic.  We got a lot of folks where alkaline city water and well water too. They got terrible copper corrosion. Other causes of copper corrosion.

Some were going to go over that in different episodes but the first thing to do when you see copper corrosion is just do a pH test very minimum if you have acid water you can start there.  Whatever you do, you have to fix that acidic water anyway.  So that’s what we recommend.

Hope that’s very helpful to you and please get your free guide by going to the site, or you can email me at Have a nice day!


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