Calcium hardness and salt rising, again

[mprzybylski]

Last summer I posted a similar thread around my CH and salt rising. I just ran the full test suite today and I'm seeing an increase in CH and salt again and I don't want it to get out of control like it did last year before I did a full drain and refill (on Nov 8, 2022). You can see my logs here.

Since that thread, I took the advice of what was written and had my soft water plumbed to my autofill and have been using that to autofill the pool this summer. On Nov 15 after the re-fill, i tested my CH at 250 and salt at 3200, keeping them at the low range as suggested. By Dec 11 the CH already made its way up to 300 (salt stayed at 3200) and it seemed to stay at that level a month later on Jan 14 (salt actually fell to 3000, but that seemed acceptable). I thought "Great! the soft water autofill is working as expected!" and that my problems had gone away. The Feb 18 test revealed the same readings so I was super happy and moved on with my life. On March 20 CH went up to 325, no issues (salt stayed the same).

April 16 tests revealed CH at 350 and salt back to 3200. May 27 readings had CH at 375 and salt at 3600, so I started to worry a bit again as we were heading into the dead of summer in AZ which is when i saw the dramatic rises last year. Sure enough, tests on June 24 revealed CH at 475 (salt went to 3400) and July 22 had CH at 500 and salt at 3600. Fast forward to today's tests and i'm at 575 with CH and 4000 with salt.

As suggested in the prior thread, I've been trying my best to keep the pH levels between 7.2-7.8, refilling 24oz of MA basically every 3-4 days (if I miss the 3-4 days I add more, maybe 30-40oz or so). I'm starting to grow a bit more concerned that something is going on with the pool that is not in my control, but I don't know what that would be. Why am I seeing such rises in CH and salt, especially having the autofill plumbed to use soft water?

There was one time when I saw my salt tank pretty low on salt so I immediately filled it, but overall i've been pretty good about keeping up with the salt levels in my WS.

 

[Rancho Cost-a-Lotta]

Try testing your fill water after the water softener for CH and Salt. Let us know what the results are.

 

[mprzybylski]

Try testing your fill water after the water softener for CH and Salt. Let us know what the results are.

On the fill water (tested at the water softener spigot that was installed when the autofill pipe was run at the same time), the CH is 25 (never even turned red, was purple and then clear blue after first drop), ph of 7.2, and TA of 90.

 

[mprzybylski]

Just wanted to bump this to see if anyone has any ideas? Or should I just expect to have to drain and refill my pool each year to get my water under control considering the environment I live in?

 

[Texas Splash]

A bit of a head scratcher. While your water seems to be quite soft after the water softener, it does still have a low amount of CH. I suspect you're experiencing a lot of evaporation in Gilbert. The actual amount may be unrecognized with the autofill doing its job, You could be losing a good 1/2 inch or so of water each day to evaporation, but the CH never drops. With the addition of new water each day, I can't help but wonder if that might explain the steady increase in CH.

 

[mprzybylski]

With the addition of new water each day, I can't help but wonder if that might explain the steady increase in CH.

Even though the new water is very low in CH? I don't doubt that evaporation is happening at a pretty quick pace, but thats what is so puzzling to me, because if its being auto filled with the very low CH water, why does it continue to rise so quickly?

 

[Texas Splash]

but thats what is so puzzling to me, because if its being auto filled with the very low CH water, why does it continue to rise so quickly?

Let's see if @JoyfulNoise has any details to contribute to your question.

 

[JoyfulNoise]

What is the CH of the raw water into your house (before the softener loop)?

And are you 100% sure that your pool auto fill line is being fed from your softener?

Most pool builders will NOT plumb auto fill lines to the soft water line for fear of soft water damage. They’ll often claim “it’s against code” but it’s not. They just don’t want to do the extra work. I had to request that my auto fill line be attached to my soft water line by the softener company that did the install and they did it for an extra fee and I had to pay the plumber separately for it (I don’t think the softener company wanted the liability). Obviously it is all fine and has only been positive experience for me.

Evaporation in the desert southwest is extreme. In the areas between Phoenix and Tucson, the pan evaporation rate of water is well over 100” per year with less than 10” of precipitation. That’s means you will evaporate your ENTIRE pool volume of water and then some in one year. If your pool is being refilled with water than has any calcium in it, your CH will increase year over year by at least the amount of CH in the fill water. If your softener regenerates a lot, then while it is regenerating (often for over an hour or more late at night), then the softener is in bypass mode and all of the water being used is hard water from the main supply. Since regeneration is usually set for the early morning hours (2am’ish), no one is really using water at that hour and so the bypass doesn’t matter. But your pool is definitely using fill water overnight (that’s when auto fills run the most in the desert) and so your pool definitely gets a good shot of bypassed hard water when the softener is regenerating.

 

[mprzybylski]

What is the CH of the raw water into your house (before the softener loop)?

Last I tested it, it was between 200-250 (that was last year when i referenced the thread in my original post). Additionally, when I refilled the pool with that water, the CH was around that same level.

And are you 100% sure that your pool auto fill line is being fed from your softener?

Yes, my pool build was a complete DIY so no builder, but the soft water autofill was added after the fact last year as well. The pipe that feeds the hose bib which I just tested the CH at 25 from is the same pipe that runs to my autofill and i have the option to toggle the autofill to use hard water (the original piping done by the plumber that did my pool plumbing) or the new line that uses soft water. It's been set to use the soft water line since it was installed last year before I emptied and re-filled my pool (I used hard water [200-250 CH from my normal hose] to fill it which was in mid November, then switched the autofill to use the soft water once it was filled (25 CH) and it hasn't been changed from that setting since.

 

[JoyfulNoise]

My guess - there’s something wrong with your water softener. If, for some unknown reason, during the regeneration cycle the softener isn’t bypassed, then brine water mixed with calcium from the resin could get into the auto fill line and then you would be sending bursts of high salinity and high CH water into the pool.

How old is your water softener and has it ever been serviced?

 

[mprzybylski]

How old is your water softener and has it ever been serviced?

We installed it when we had the house built, so that would put us at right around just over 6 years old. It was not serviced, but it was checked and validated when we installed a whole home filtration system about ~2-3 years ago.

 

[JoyfulNoise]

We installed it when we had the house built, so that would put us at right around just over 6 years old. It was not serviced, but it was checked and validated when we installed a whole home filtration system about ~2-3 years ago.

Water softeners have rotary control valves in them often called “Clack valves” (because Clack used to be the biggest supplier of them). These control valves are very complicated multiport valves with several rubber o-rings as well as a spider gasket (similar to the spider gasket one finds on a pool MPV). These components wear out over time and the o-rings especially need to be changed. At the 4 year mark, I noticed my water softener had a very slow drip at the waste water line. When the technician came to check the Clack valve, it needed to have the internal MPV cage and o-rings replaced as the unit was dripping water into the waste line and there was definitely water making it past the bypass during regeneration.

I suggest you have the company that installed it or a qualified plumber come out and check the clack valve. I bet it’s allowing brine water into the bypass.

It’s about a $100 part to replace in full and takes all of 30mins to replace. 6 years is a long time for a valve that runs every couple of days.

 

[mprzybylski]

@JoyfulNoise Thank you for all of your replies. Considering everything else, I think you are right in that the issue may be my WS as I can't think of anything else that may be impacting this at this point. I feel like I've done everything I can to avoid this issue yet its still here, so I'll have a plumber come out to take a look at it. Appreciate the insights.

 

[proavia]

It's also possible the softener settings are incorrect. It may not be regenerating often enough and it's running out of soft water before the regen cycle.

How many grains is your water softener rated for?
How many gallons between regen cycles?
Electronic or mechanical timer clock?

The "Clack" valve @JoyfulNoise mentioned might also be a "Fleck" valve. If you have a service done, ask what you have.

 

[JoyfulNoise]

It's also possible the softener settings are incorrect. It may not be regenerating often enough and it's running out of soft water before the regen cycle.

How many grains is your water softener rated for?
How many gallons between regen cycles?
Electronic or mechanical timer clock?

The "Clack" valve @JoyfulNoise mentioned might also be a "Fleck" valve. If you have a service done, ask what you have.

Gene, spot on!

Modern water softeners are usually the “demand” type water softeners which measures the flow of water through the softener and then regenerates once you’ve reached the demand capacity limit. On my softener, that’s set to 1766 gallons. Usually the demand set point takes into account the full capacity of the resin, the average daily use of water and then adds in (subtracts out, really) and safety margin to ensure that you never run out of soft water. As the resin ages, it loses capacity, especially if the input municipal water has a lot of chlorine or chloramine in it OR if there is iron in the water. Chlorine oxidizes the resin and destroys it and iron will irreversibly bond to the resin and reduce its capacity.

A pool auto fill is often just a tiny trickle of water all day long and it is rarely enough flow to trigger the internal flow meter of the softener. And so the softener capacity is being used up by the pool but the softener isn’t taking that into account and so it’s probably running out of softening capacity in between regen cycles. This will lead to increased CH.

The problem is you are also seeing your salinity go up as well. That’s troubling because acid additions alone don’t add a huge amount of salt and you are seeing hundreds of ppm changes. That’s a lot of salt. This is why I suggested checking the softener valve - a brine leak would add a significant amount of salt because the brine is nearly at the saturation value of salt in water which can be as high as 40‰ (parts per thousand).

 

[proavia]

Gene, spot on!

Modern water softeners are usually the “demand” type water softeners which measures the flow of water through the softener and then regenerates once you’ve reached the demand capacity limit. On my softener, that’s set to 1766 gallons. Usually the demand set point takes into account the full capacity of the resin, the average daily use of water and then adds in (subtracts out, really) and safety margin to ensure that you never run out of soft water. As the resin ages, it loses capacity, especially if the input municipal water has a lot of chlorine or chloramine in it OR if there is iron in the water. Chlorine oxidizes the resin and destroys it and iron will irreversibly bond to the resin and reduce its capacity.

A pool auto fill is often just a tiny trickle of water all day long and it is rarely enough flow to trigger the internal flow meter of the softener. And so the softener capacity is being used up by the pool but the softener isn’t taking that into account and so it’s probably running out of softening capacity in between regen cycles. This will lead to increased CH.

The problem is you are also seeing your salinity go up as well. That’s troubling because acid additions alone don’t add a huge amount of salt and you are seeing hundreds of ppm changes. That’s a lot of salt. This is why I suggested checking the softener valve - a brine leak would add a significant amount of salt because the brine is nearly at the saturation value of salt in water which can be as high as 40‰ (parts per thousand).

I'm fortunate that my softener flow meter "sees" my autofill flow - but, as you point out, many don't.

I visited the Terry Love forums and got recommendations for my softener settings, based on my water hardness.
My 60,000 grain softener is set now for just over 48,000 grains. This balances salt use and water used for regen.
Here's the thread I started back in 2019, right after I replaced my old, non-functioning and undersized softener.

Fleck 5600SXT 64K Settings Help Requested

Requesting help setting up my softener for best efficiency (balance of salt/water use each regen). Fleck 5600SXT 64k - 12x48 tank 2.0 ft3 10% resin (per dealer) Brine tank - 14.5x14.5x34 Hardness runs 5-20 grains, avg 16.5 (city report) City water BLFC - 0.5 gpm Salt - 1.5# min DLFC - blank...

terrylove.com

It isn't a perfect setup. And the water hardness can change throughout the year.
There are times that the softener runs out of soft water before the gallons count all the way down - my wife lets me know the water feel "squeeky" . That's my cue to do a manual regen.

I would guess it's either the settings worn parts. More likely worn parts allowing brine (water saturated with salt) into the plumbing, causing the issues the OP is seeing.

 

[JoyfulNoise]

Yes, I know the “squeaky water” complaint well …

My dual tank softener is a 52k grain tank but it has a GAC tank before the resin bed. The GAC removes a lot of junk before the softener resin sees the water. Downside is the GAC needs to be changed every 18 months but it saves on resin changes. Chlorine really destroys the softener resins, even the higher cross linked kinds, and it’s unfortunate because the resin changes aren’t cheap.

 

[mprzybylski]

How many grains is your water softener rated for?
How many gallons between regen cycles?
Electronic or mechanical timer clock?

Because it was purchased 6 years ago (and we were new to AZ and never had a softener before) I don't quite remember all the details, but I believe it is 48,000 (it is the Fleck 5600 SXT which it looks like is what you have as well). As for the settings, I'll be 100% transparent and say that I have no idea. I trusted what they set up when they installed it because of my incompetence when it comes to the subject and then the plumber that installed the soft water line to the autofill also adjusted it at the time. But what those settings are? I have no idea, and to top it off I don't even really know how to check because sadly I never learned to use it (again, blind trust). In retrospect, its clear that I need to revisit that and learn the controls and how to read it properly, so I'll do that.

 

[Texas Splash]

I have a simple Kenmore water softener, but I find that I have to change the resin about every 7-8 years.

 

[proavia]

10" x 54" seems to be a pretty standard size for a 48,000 grain capacity tank.
There is normally 1.5 cu ft of resin in a 4ik unit.

That is the same valve I have - Fleck 560sxt

https://www.pentair.com/content/dam/extranet/web/nam/fleck/manuals/42683-fleck-5600sxt-upflow-manual.pdf

As you see, Pentair now owns them.

As for settings, follow my link in post #16. Then start your own thread specific to your valve and tank size.

At 6 years in service and with our water here in the East Valley, it may be time for a resin replacement.

Maybe @JoyfulNoise can enlighten us on the GAC pre-filter he has.