Acid Neutralizer vs. Chemical Feed System: Which One Should You Choose?

Caller "They wanted to do a water softener and a 35 gallon chemical feeder system. I'm not a well person, but with my hardness at 3, that seems a little too aggressive to me."

Aidan "No, we don't recommend chemical feed systems. They're a nightmare. They put that in so they can come out and service it every month. You need a sediment filter and a neutralizer."

That was a Maryland caller this spring, a month into a new house, with a pH of 6.9 and a quote on the kitchen table. Most people who ask me this question have the same quote in front of them. This page is the long version of what I told him.

What each system is

An acid neutralizer is one tank of calcite (crushed limestone) on the main line after your pressure tank. A chemical feed system is a pump that injects soda ash into that same line every time the well runs. Both raise the pH of acidic well water. They do it in very different ways, and the difference is what you will be doing in the basement for the next twenty years.

The calcite tank

Water comes in at the bottom, flows up through the calcite, and the acid in the water dissolves a little of the limestone on its way through. That is what raises the pH. It is self-regulating: the more acidic the water, the more calcite it dissolves, and once the water is neutral it stops. The non-backwashing tank I sell has no motor, no circuit board, no drain line and no cord. The calcite level drops slowly as it dissolves, and when it gets low you pour a bag in through the fill port on the side. A Pennsylvania caller this spring asked me whether our pH system was "an electronic type dosing, or just like a dosing pump." It is neither. It is a tank, 13 by 54 inches, standing next to the pressure tank. The how an acid neutralizer works page goes through what happens inside it.

The chemical feed system

You mix soda ash powder with warm water in a solution tank about once a month. A chemical feed pump draws from this tank and injects the solution into the water line whenever the well pump runs. The solution tank is 15 to 30 gallons with the pump on its lid. Done right, the treated water then goes into a retention tank, usually 80 to 120 gallons, so the soda ash has time to blend in before it reaches your faucets. Some systems use sodium hydroxide instead of soda ash; Penn State's extension service notes that soda ash is preferred because sodium hydroxide is extremely caustic. The soda ash vs acid neutralizer page covers what soda ash is and how to switch off it.

Under three minutes on camera: the parts a soda ash system needs, the monthly mixing, what happens when the pump fails, what to do at pH 4, and what each one costs.

Calcite tank vs feed pump, side by side

The calcite tank asks you for one bag every few years. The feed pump asks you for a mixing job every month and a working pump every day. Everything else in the table follows from that.

What if my pH is under 5?

The lowest pH I have fixed with a calcite and FloMag blend is 3.67. Same tank, more FloMag in each bag. FloMag is magnesium oxide, a stronger pH raiser than calcite, and it is mixed into the calcite bag by bag before the bags go in the tank. The lower your pH, the more FloMag goes in each bag. Above 5.5, calcite alone does the job. Under 5.5 the 2.5 cubic foot tank ships with the blend. Under 5, call or text me with the lab number and I will give you the ratio for your water; the FloMag page has the ladder I work from.

You will hear from dealers that calcite cannot keep up below 5 and you need a feed pump. When we were a service company, the low-pH houses were where we took feed pumps out and put calcite tanks in, not the other way around. You end up with the same tank no matter what your pH is. What changes is what goes in it.

Two things worth knowing before you worry about this. Of the 366 lab tests my customers have sent in, about one in six came back acidic at all, and 1 came back under 5.0. The number on a hardware-store strip is not the number to size from; a lab pH is. If you do not have one yet, the certified well water test ($199) reports pH and hardness from one sample.

Does the calcite tank make water hard?

Yes, a little. Calcite adds about 3 to 6 grains of hardness. A soda ash pump adds none. Grains are the unit a hardness test reports in. If your water is at 4 grains now, you might land at 8 to 10 after the tank. That is the one real point in the feed pump's favor, and it is the reason the argument comes up on plumbing forums.

Here is how I put it to people. The calcium the tank adds is not a side effect; it is the fix. Penn State's extension service says it plainly: the neutralizing tank "will increase the hardness of the water, but this is necessary for proper corrosion control." Acidic water is eating your copper because there is no limestone in it. The tank puts some back. If you do not want the hardness at your faucets, a softener goes in after the neutralizer and takes it out again, and you can add the softener later if you want to see how the water feels first. The 2.5 cubic foot tank with a 48,000 grain softener is $3,295 as a package. The acid neutralizer and water softener page covers the order and the sizing.

When a chemical feed pump makes sense

A feed pump makes sense when you cannot add any hardness and will not run a softener, or when someone else is paid to keep it running. Those are real cases. Penn State lists the two honest advantages: the soda ash adds no hardness, and because the pump goes in ahead of the pressure tank there is no pressure loss.

Even a plant near Baltimore with a well serving about 60 people, calling me after an accident with their caustic (sodium hydroxide) pump, went to a calcite tank with a softener behind it.

So why do I not sell one? We took hundreds of them out over 25 years as a service company. People were fed up with the cost of repairing the pump and with dealing with it every month, and they would forget about it. If you do not mix the chemical right, it can be too strong and be toxic; if it is too weak, it is worthless. The caller in the opening had it right when he said the quote seemed aggressive for his water. A company that installs a feed pump gets a monthly service visit out of it. A company that ships a calcite tank gets a phone call every two or three years for a bag.

Been quoted a chemical feed pump?

Send me the quote you were given

Send a photo of the quote and your test results. I will tell you whether your water needs it, and what I would put in instead.

Text Aidan443-277-2204 Call800-460-5810Aidan

8 AM to 5 PM Eastern, seven days a week. A real person, not a call center.

What each one costs to own

The 2.5 cubic foot calcite tank is $1,495 shipped, or $1,695 with the FloMag blend, and after that it costs one $145 bag of calcite every 30 to 36 months. A soda ash system installed correctly, with the retention tank, runs about $2,000 to $3,000. After that come the soda ash and the pump repairs. One of my customers ran a soda ash system for ten years before switching; her review is in what buyers who switched wrote.

I am not going to give you a yearly soda ash budget or a pump-replacement price, because I do not sell them and I would be guessing. For the calcite side, the acid neutralizer cost page has every size, what a plumber charges, and the ten-year total.

Acid injection is the opposite system

An acid injection system pumps acid into the water to lower a pH that is too high. A soda ash feed pump does the opposite and raises a pH that is too low. If your pH is under 7, skip this section; an acid injection system is not for you, whatever the name on the quote says. The EPA's recommended range for drinking water pH is 6.5 to 8.5, and of the lab tests my customers send in, about 3 in 100 come back above 8.5. High pH usually comes with hard water, not corrosion. We do not carry an acid injection system; when someone calls me with a pH of 9, I tell them a softener brings it down a little and there is not a whole lot else to do.

What buyers who switched wrote

Every reviewer below is a verified purchase through our store. Reviewer names appear as the buyers wrote them.

Frequently asked questions