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Community and Q&A

Water softeners and treatment

Dustin_7022224 | Posted in Mechanicals on

We are building in an agricultural zone and about to drill our well. It’s got me thinking about water condition and treatment.  Our current house, on the lot adjacent, uses a traditional water softener requiring regular addition of salt.

Our new mechanicals and water main will be in the basement. We are also on a septic system and will be conditioning the home with an open loop geothermal unit.

I’m not excited about dumping a bunch of salt into the marsh/pond on our property, where the effluent bypassing our septic system will go (along with sump pump water), nor do I want to lug all that salt into the basement.

Does anyone have good suggestions or advice for softening or otherwise treating our water? What about the water going through the geo unit (wanting to avoid iron deposition, etc leading to premature failure.

FYI, I plan to plumb the domestic water using Aquatherm PP-R pipe and fittings.

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  1. Expert Member
    BILL WICHERS | | #1

    You really need to know what is in your water before you can properly design a water treatment system. My well has a LOT of iron and manganese, some sulphur, and is really hard. I also have some sediment in the water. I use a 25/1 micron filter cartridge as a first stage, then a greensand type iron filter cartridge (which also gets manganese and sulphur, among other things), then an activated carbon filter. I feed this water to the kitchen sink cold side directly. Everything else goes through a water softener.

    If I were to design the system again, I’d use a resin-type iron filter which would be much cheaper to operate. I spend about $80 per iron filter cartridge and I replace it about 3 times a year. The resin type filters last about 10-15 years and cost around $1,000 or so which makes them a better value over time.

    The “no salt” cartridge-type water softeners have a very short life and I don’t recommend them.

    Get a water test. You need to know hardness, iron, manganese, and sulphur as a starting point. If you’re in an agricultural area, test for fecal coliform and nitrates too. From there, you can start to figure out what you need to do to treat your water properly.

    I would order water for the geothermal loop. Order water that has been conditioned and treated for your heat plant and don’t use the well water. If your system is a closed system, you shouldn’t have to worry about makeup water. If you have an open system, use RO water for makeup water.


  2. Dustin_7022224 | | #2

    Thanks Bill. Any suggestions for getting the water tested or specific info I need to ask for in the well 'report' when it's drilled?

    We plan to have an open loop geo system, from the constant pressure pump to the house, including geo. I'm told to plan for 6 GPM for the geo heat pump. We could look at RO for that, if it's best.

    Why do you bypass the softener for the cold water in the kitchen? Just taste preference? Sodium concerns?

    1. Expert Member
      BILL WICHERS | | #3

      You want the basic health stuff (your county can tell you what you need for that since it varies a little based on where you are), plus the things I mentioned. You can ask for anything else you’re specifically concerned with, but they charge more as you are more tests.

      6GPM sounds like a circulation and not a consumption number. Your normal operation should usually only be for makeup water, to replace water lost to evaporation and leaks. RO systems are usually rated in gallons PER DAY, with 50 GPD being a typical residential system. My guess is that could supply your thermal loop too, but double check. You’ll probably need a bigger pressure than than normal for your RO system too — which is beneficial for general use as well. The advantage to use RO water for makeup water is that you avoid the buildup of minerals and other things in your thermal system which is a really good thing for longevity of the system. You don’t want to use pure RO water though, so start with premix stuff and only use RO for makeup.

      I bypass the softener for my kitchen sink for sodium concerns. I have high blood pressure, so it’s more important for me. I also have VERY hard water here, and since water softeners work on an ion exchange principle, the more calcium in your water before softening, the more sodium you get in the output water since the softener replaces calcium ions with sodium ions. The downside to bypassing the softener is you get more mineral deposits on dishes, but we use a dishwasher for most washing and that’s on the softened hot water. We use our RO water for things like coffee and tea which keeps those machines looking like new (icemaker too!).

      I highly recommend RO systems for anyone with a well. I’ve found that RO water is great for cleaning things too, often even better than commercial cleaners! It evaporates cleanly away so it leaves no residue. It works better than anything else for cleaning our stainless steel appliance surfaces. We do most basic cleaning with the RO water alone, and use a bleach-based cleaner when we need to sterilize surfaces.


      1. Dustin_7022224 | | #4

        Still not quite following on the make up water for the geo. I think we are talking abou two different things. We plan to use an open loop system, which my understanding means up to 6 GPM is pumped out of the well, through the geo, and is discharged out to the wetland/pond on our property.

        You seem to be mentioning make up water, I think referring to a closed loop system maybe.

        Otherwise, greatly appreciate your advice. If any suggestions about treating the water specifically that goes through the geo, seeing that RO is not feasible given our open loop system and planned usage, please share.

        Will definitely look into RO for specific uses, as you mention. Did you not plumb it to your kitchen sink because you don't like the taste? Or did I misunderstand?

        1. joshdurston | | #5

          For GSHPs on open loop systems you need to get a water test, and select the proper HX type. Also depending on the temperature you may be able to reduce the flow rate to as low as 1.5GPM per ton.
          For harsher water conditions you may need a CuproNickel type Coax HX instead of the standard copper. Some water is not suitable for GSHPs. The manufactures have details in the installation guides about water quality, and are very specific about various limits.

  3. Jon_R | | #6

    > What about the water going through the geo unit

    It's not affordable to soften open-loop water, but pH adjustment might be.

    If you use open loop geo, be sure to set the system up so that it can easily be acid cleaned without air getting into the system. Frequent/easy cleaning means you can use water that would normally be considered unsuitable for open loop.

    I'm happy with RO water for drinking.

  4. Expert Member
    BILL WICHERS | | #7

    Yes, I was thinking in commercial terms where an “open” system evaporates water as part of the cooling process, and a “closed” system is not open to the atmosphere anywhere. We don’t ever discharge water since it’s wasteful. The closest commercial system is to recirculate water from a pond or stream, pumping the water out of the pond, through a heat exchanger, and back to the bond. Using a well pump wouldn’t be economical in these systems.

    RO would be great for an open system for the same reasons it’s great for makeup water: there is no issue with mineral buildup. The problem is that you’d need a VERY large RO system to supply this amount of water, which would probably not be economically practical. RO systems aren’t very efficient in terms of water use, either, since a lot of water passes through, flushes the membrane, and is lost as waste water.

    I have no problem drinking the RO water and do so all the time. It’s like bottled water, but continuously available.


  5. walta100 | | #8

    Do some water softeners use a lot less than the standard models? The control on my softener allows me a setting for the waters hardness and the time of day.

    I am on a well and have a RO system used for drinking and cooking. My RO system has a permeate pump that has worked well for us. A permeate pump captures the energy from the escaping waste water and uses it to force water thru the membrane filter reducing the amount of wasted water.


    1. Expert Member
      BILL WICHERS | | #9

      Yes, some water softeners use more salt that others. The reason is that the water softeners don’t really know how much salt is needed for any given recharge cycle, they guess. With better softeners, You tell the softener how hard your water is at install time, and then it tracks how many gallons you use with a flow meter. The softener then knows based on its capacity, the harness, and the amount of water it’s treated, the approximate amount of salt water it needs for a recharge cycle and also when to run the recharge cycle. It’s still just guessing though — the softener doesn’t really know exactly how much of the ion exchange resin is loaded and needs to be refreshed. Other things also factor in, like the amount of iron in your water.

      There is also the concept of a “reserve” in the softener. This is extra reserve softening capacity that the unit makes sure is always available, and it does this by initiating a recharge cycle before you have really maxed out the capacity of the unit. This allows you to take a bath on the evening when the recharge cycle is about to run and not have had water, for example. The downside to doing this is the recharge cycle is “wasting” more salt by being sized for more recharge capacity than hand usually actually been used.

      The best solution is a dual tank softener. These units switch from one tank to the other at recharge time. This has two big advantages: the first is that it means you never use hard water when the softener is on bypass during a recharge cycle. The second big advantage is that there is no need to keep any “reserve capacity” available, because you can just switch to the second tank when the first is used up. Recharge cycles occur whenever the tank switches. This allows the recharge cycle to be more optimally sized for the actual need since you can better count on the resin in the tank being fully loaded at recharge time. In a green sense, dual tank units are greenest since they’re most efficient in terms of salt usage.

      When I have to replace the resin (or controller, whichever comes first) on my softener in the next few years, I’m going to upgrade to a dual tank unit. You can get new control valve assemblies and tanks separately, so I plan to get another tank the same size as my current tank, then install a dual-tank control valve. This saves a little money, and then I have the advantages of the dual tank unit.


    2. Dustin_7022224 | | #12

      Anyone have recommendations for RO systems? Perhaps a brand/manufacturer - or ones to avoid? Same for softeners. I've heard good things about Fleck.

      1. Expert Member
        BILL WICHERS | | #13

        Fleck makes the control valves on the softeners. They have a good reputation and dominate the industry. The rest of the softener is basically just plumbing parts — tank, resin, some piping. The most important thing is to size it correctly.

        If you have really hard water, or (especially), if you have something big you fill periodically like a big jetted tub in your bathroom, I strongly recommend a dual-tank softener. Dual tank systems are more efficient with their salt usage since they don’t have to maintain any reserve capacity.

        APEC water systems makes pretty good RO systems that are reasonably priced. Use something bigger than the basic 3 or 4 gallon tank though. I used to have 3 gallons worth of tank (two 1.5 gallon tanks in parallel), and recently added a 14 gallon tank. The bigger tank makes the system MUCH more useful!


  6. Dustin_7022224 | | #10

    Thanks for all the helpful comments. Does anyone have or know about 'salt-free' water softeners?

    1. Expert Member
      BILL WICHERS | | #11

      They typically have a very short life in terms of the number of gallons they can treat before they need replacement. Water softeners work by ion exchange, swapping out calcium ions (which make the water “hard”) , for something else, usually sodium. That means you always have a waste material to deal with as a byproduct of the softening process. As far as I know, there I no filter available that can remove any significant amount of calcium without some type of flush cycle and use of a sacrificial material like salt.


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