Water Softener

My water softener is in — at least physically installed — but not yet operational.  The big hold-up is the new water supply system, not yet done.  In the meantime, I have some thoughts about the process of selecting and operating a water softener.

If you’re thinking about installing a water softener, keep reading.  If not, maybe better to just jump down to the pictures :-)

I did some research before buying my system, but not enough.  I just looked at the vendors’ web pages, and the advice they offer for proper sizing, programming, and operation — woefully inadequate.  More questions than answers.  After making the purchase, I found some forums that were much better. 

I think my big mistake was in sizing the system too large.  There is just one of me, and I’m not a big water user, but I wanted a good flow rate.  A water softener is a big drag on water flow, and if your water pressure is already low, you could end up with some frustrations.  Second, you can operate your system to be more efficient or less so.  For greater efficiency, you should select a system with a larger nominal capacity than your water use might suggest.  Third, you can get by with a smaller capacity system if you regenerate (backflush) more often.  And fourth, a large capacity system doesn’t really cost too much more than a smaller one.

The water softener I bought seems to be mainstream.  There are simpler (and cheaper) models that contain all the parts in a single container/tank.  There are more expensive models with more bells and whistles, including those from name-brand suppliers (Culligan, etc.).  Mine is pretty much a generic system from a small internet supplier; these tend to all use the Fleck 5600 SXT electronic controller bundled with the various other pieces needed to complete a whole system. 

These systems generally work as follows:  hard water comes into the house, enters the softener, where it is routed through a tank containing treated resin beads that bind with the minerals in the water (calcium and magnesium), removing them from the water.  The softened water then continues through your house. 

Obviously, the resin beads gradually bind with so much mineral that they lose their potency.  The electronic controller then isolates the resin tank and uses salt water from a second (brine) tank to flush the minerals off the resin beads, restoring their potency.  The salty flush water, loaded with minerals, is then pumped down the drain, and a new cycle starts.  This process is called regeneration. 

How does the electronic controller know when the system should be regenerated?  Older and simpler systems initiate regeneration based on time — say, every week.  This works well enough if your use of water is consistent, but a better solution is to measure how much water has gone through your system (using a meter), because that is the real measure of how much of the system’s softening capacity has been used. 

The Fleck 5600 SXT uses a meter, but also has a timer backup. 

During regeneration (when the salt water is flushing the resin beads) the control valve directs the hard water coming into the house to continue through the system without being treated, so people program the regeneration to occur during the middle of the night, or any time nobody will be using water. 

As mentioned, the system uses salt water (brine) to flush the minerals off the treated resin beads.  The brine tank must be filled with salt at regular intervals, so this is not an install-and-forget type of thing.  You can buy bags of salt from home centers or water treatment companies.  There are different kinds of salt — both in the size of salt granule and the chemical composition.  The most common and cheapest is sodium chloride (NaCl), the same as table salt, although you could not actually use table salt because the granules are too fine.  If you use sodium chloride, you would have to send the flush water down a drain; if you sent it outside, it would kill the plants. 

I am going to use potassium chloride because it is environmentally more friendly, and I initially had intended to pump it outside to irrigate my palm trees because I read that potassium is a nutrient  that plants like.  I had gone so far as to run the flush discharge line out through the wall to the backyard, but overnight while in a semi-dreamlike state, I remembered my calculations on the amount of salt used (close to 200 pounds over the course of a year), and imagined what that would look like next to the discharge pipe after the water evaporated.  Especially after ten years.  Hmmm.  Now it will go down the drain.

Water softeners come in various capacities, expressed in grains of minerals to be removed.  Most common are 32,000, 48,000, and 64,000, which is how many grains of minerals they can remove before the system needs to regenerate.  How big should you get?  It depends on how much water you need to treat, and how hard your water is.

The how much water question is per regeneration cycle.  If you have a well, they say you should regenerate every week (about), and if you are on city water (less iron to degrade the resin beads), you should regenerate every two weeks.  These seem to be rules of thumb only—a lot of fudging in this business.  Since my system has so much extra capacity, I’m going to base my set-up on a three-week cycle (we’ll see how that works out!).

So, say you’re on city water and you plan to regenerate twice a month, and you know how much water you use every month (from your water bill).  Let’s assume you don’t plan to treat the water you use outside to water your yard, so subtract that amount (or use a water bill from the middle of winter).  Divide that number of gallons by two, which gives you gallons of water per regeneration cycle. 

Next, you need to know how hard your water is — that is, how many grains per gallon of minerals.  Soft water has no more than 3 grains per gallon; very hard water has more than 10.  (My water is extremely hard, with 26 grains per gallon.)  Multiply the water hardness in grains/gallon by the number of gallons used per regeneration cycle, and that gives you the number of grains your system must remove.  But we’re still not done.

Say you need to remove 32,000 grains of the bad stuff.  Choose a 32,000 grain capacity system?  Well, no.  That system could remove that much hardness, but it would waste a lot of salt.  The same system rated for efficient operation would have about half the capacity, so maybe you would then want to buy a system rated for 64,000 grains. 

Systems are also rated for flow rate in gallons per minute.  Pushing all that water through a tank filled with tiny resin beads really slows down the flow.  That’s why I ended up sending unsoftened water to my urinal (which has a very high flow rate requirement).  It’s also why I bought a system much bigger than my modest water usage would seem to dictate, although after further research I would have gotten a smaller capacity system (had I to do it again).

Physically, nominal system capacity is determined by the volume of resin beads contained in the main treatment tank.  A 32,000 grain system uses one cubic foot of resin beads, 48,000 uses 1.5 cubic feet, and 64,000 grain systems have a tank that will hold two cubic feet of resin beads.  Bigger tank, larger diameter, higher flow rate—at least that seemed to be the result. 

 Anyway, how the system works is a function of how you program the controller, and the instructions that come with the systems, and internet instructions, tend to be over-simplified and generic.  It’s a complex subject, and at times my research pointed to more art than science. 

There are some things that are important when programming the controller.  First is system capacity.  A lot of instructions just say enter the nominal advertised system capacity — not very efficient, but the people giving instructions would have to go off on complex tangents to do a good job (assuming they understood the science).  They just want to tell you what numbers to enter in their three-minute video.  Easy typically wins out over optimum (and complex).

But for efficiency, if you bought a 64,000 grain capacity system (like me), you might want to input something like 40,000 for efficient operation (as an example).

There are a number of other fairly straightforward inputs, and then there are a few more critical items, like brine fill time.  Brine fill time is basically how much salt you want to use per regeneration, a measure of efficiency.  This is expressed in grains of hardness removed per pound of salt.  In California, water softeners must be able to remove at least 4000 grains per pound of salt (although they can be operated much less efficiently).  If you operate them carefully, you can achieve significantly greater efficiency.  There are limits, of course.  

I’m aiming for 5000 grains of minerals removed per pound of salt used.  More practically, the calculation will be made for pounds of salt per cubic foot of capacity.  I’m looking to use 5 pounds of salt per cubic foot (of resin) capacity (this number comes from internet forums on water softeners; you can do better, but then setting up and operating the softener more efficiently gets to be pretty fussy).  Since my system is two cubic feet, that means 10 pounds of salt per regeneration.   Brine fill time determines salt usage.  One gallon of water will dissolve three pounds of salt, or 3.3 gallons will dissolve 10 pounds of salt.  The rated brine flow rate of my control valve (can vary depending on size of nozzle) is 0.5 gallons per minute, so I will program the controller for a brine flow time of seven minutes.  So during the regeneration, the controller pumps salt water from the brine tank into the resin tank for seven minutes, introducing the ten pounds of salt (in solution). 

If you really want to control how your softener will operate, you have to do these relatively simple calculations.  You can actually get into a lot more complexity, or you can just plug in the values that the generic instructions provide.  If only there was an app for this . . .

But the ultimate test is in the testing, that is, get a test kit and measure how soft your water is after the softener has been operating for awhile.  Measure in the middle of cycle and again at the end of a cycle (just before regeneration), and then make adjustments.  Trial and error.

Alternatively, you can hire a local water treatment company to do the whole thing for you.

Sigh. 

And now for the good part of this post — the pictures.

This is the set-up; the water softener is in the laundry/utility room, opposite the washer and dryer and water heater.  The tall cylindrical tank holds the treated resin, and has the electronic controller on top.  The unsoftened water comes down from the attic through the 1" white PEX line on the right and the softened water goes through the PEX line on the left back up to the attic for distribution.  The tall rectangular container is the brine tank; this is where you dump the salt (the controller fills the tank with water up to the correct height via a shut-off valve inside the tank). 

This is a view from the left side.  The air handler for the future heat pump will be installed to the right of the water softener, and there will be a laundry folding table to the left.  The controller pulls the brine from the brine tank into the resin tank through the thin black tube you can see to the right of the tank.  To the left is the blue PEX line going into the white PVC pipe mounted to the wall—initially out through a hole in the wall to outside discharge.  That will now be changed.

The PVC flush line that will get disappeared:

This is the one of the floor drains in the laundry room, with the grate modified by gluing a short section of 2" ABS pipe to it to keep discharge water from splashing on the floor.  In this photo, the clear plastic tube is the overflow line from the brine tank (which should never be used unless there is a malfunction of the shutoff valve inside the brine tank).  I will soon be routing the flush line into this drain, and after the heat pump air handler is installed, its condensate drain line will also be routed into this floor drain. 

This is the control head for the water softener.  Once it is plugged in, it will read out the remaining gallons of water before regeneration starts, and other useful information.  It is also where you program the controller, using the three buttons.

The next photo shows where the water enters and leaves the control valve.  Toward the left, the domed shaped section fastened with four screws and with a gray wire exiting from its top, is the water meter.  There are two types of meter — this "paddlewheel" variety and (I believe) a more current and much smaller "turbine" meter.  You have to program in which type of meter you have, and the instructions may tell you the wrong one.  I think I was sent an older device, and the instructions tell you to program the code for the turbine meter.  Be sure to check.

Toward the right is the manual "bypass valve" which allows you to send your water through your house without it going through the water softener.  This particular one is plastic and is threaded for 1" pipe — interesting because the vendor advertised that the water softener I ordered would come with a stainless steel bypass valve threaded for 3/4" pipe.

Last photo — I installed a couple of pressure gauges to show both intake pressure and discharge pressure, thereby indicating the pressure drop through the system.  The more clogged the resin beads (with minerals), the greater the pressure drop.  When no water is flowing through the system, the pressures will equalize (be the same), but when water is flowing, you can read the pressure drop.  This is a non-essential addition, but perhaps useful. 

Coming up next:  I've ordered the master bathroom vanity top from an internet fabricator (after first getting an estimate from a local contractor — almost 100% higher bid).  That should be here in about ten days, maybe.  In the meantime I will be working on the water supply system (nighttime temps down to around 60˚should enable some morning attic time), although I just had to order some more fittings, and two of them are back-ordered 3-4 weeks.  I'm also going to start working on connecting the gas line for the new water heater — more attic work.