Question: auto fill connected to water softener sys (Potassium)

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,378
Tucson, AZ
Potassium is fine. Almost all potassium compounds are highly water soluble a d thus have low scaling potential even at high pH. The only downside is cost - potassium chloride is more expensive than sodium chloride to regenerate softener resin with. But if you don’t mind paying extra, then no big deal.

You’re water may start to taste sweet though .... potassium ions tend to activate sweet receptors on the tongue.
 
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HermanTX

Gold Supporter
May 20, 2020
782
Katy TX
I have been using KCL in my water softener for years and it is also the fill for the pool as well. I have had no issues with water chemistry. My fill has high Alkalinity but zero Calcium. In fact I lose calcium in the pool over time and have to add it occasionally. You may want to test your fill water to understand the changes it may make to the pool when added.
 

FnC80

Gold Supporter
Aug 23, 2017
75
Manvel, TX (Houston)
I have my auto fill tied to my water softener as well. It’s not potassium, but as stated previously I find my pool loses calcium over time and costs a bit extra to increase it. Though I find it better to add over time than worry about getting too high and have to drain and refill.
 
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Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,208
Central California
So far my pool has been pretty even-steven CH-wise. @JC707, you might consider plumbing the way I did. I replumbed my auto-filler to my softener, but I also maintained the original connection to the city water. I've been running it 100% soft water since doing that, but I left the hard water connection in place so I could switch back easily, with the twist of a couple valves. I did that in case I ever wanted to add CH to the pool. It'd take a while, but it's free and effortless.

The other reason I did that: my softener is on my house's interior loop, so when I turn off the water main to the house, the softener goes down, too. My hard water connection is plumbed to the exterior irrigation loop, which branches off before the house main, so it stays on even when the house is shut off. I once had a pipe burst while on an extended vacation, which destroyed my entire home. So I now turn off my house main while away. Which means my auto-filler would be off, and that can't be so during the summer. So I turn off the house and switch the pool over to city water while away. House interior is safe but pool and garden still get water.

Here's how I did it, if you're interested:

#76
 

wireform

Silver Supporter
In The Industry
Aug 15, 2017
1,582
Spring Valley, NY
I can see the softener being able to top off for evaporation loss but if you use more water than its capacity won't it just pass through the softener and not really change the water quality and it being like straight from the municipality ?
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,378
Tucson, AZ
I can see the softener being able to top off for evaporation loss but if you use more water than its capacity won't it just pass through the softener and not really change the water quality and it being like straight from the municipality ?
Yes.

Pool autofills are very low flow and typically do not register on the internal flow meter of most Clack/Fleck valves. So the constant trickle of water does run down the softener faster even since the valve doesn’t pick that up. Most valves are programmed with enough reserve capacity in-place to offset the extra overrun use but it is quite easy to have some water hardness break through.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,378
Tucson, AZ
So far my pool has been pretty even-steven CH-wise. @JC707, you might consider plumbing the way I did. I replumbed my auto-filler to my softener, but I also maintained the original connection to the city water. I've been running it 100% soft water since doing that, but I left the hard water connection in place so I could switch back easily, with the twist of a couple valves. I did that in case I ever wanted to add CH to the pool. It'd take a while, but it's free and effortless.

The other reason I did that: my softener is on my house's interior loop, so when I turn off the water main to the house, the softener goes down, too. My hard water connection is plumbed to the exterior irrigation loop, which branches off before the house main, so it stays on even when the house is shut off. I once had a pipe burst while on an extended vacation, which destroyed my entire home. So I now turn off my house main while away. Which means my auto-filler would be off, and that can't be so during the summer. So I turn off the house and switch the pool over to city water while away. House interior is safe but pool and garden still get water.

Here's how I did it, if you're interested:

#76
I had two 1/4-turn shutoff valves installed - one before the softener and one after it so that I can either turn off the water to the softener, cutting off the house and the pool autofill line, or just turn off water to the house and leave the softener active along with the pool autofill line. That way, on vacations, the pool is still able to get water.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,208
Central California
I can see the softener being able to top off for evaporation loss but if you use more water than its capacity won't it just pass through the softener and not really change the water quality and it being like straight from the municipality ?
I was quite worried about this very thing myself, when I first converted the plumbing. Matt helped me calculate the expected amount of soft water used, and it was well below my softener's capacity (helped by the fact that I don't have a big family going at it 24/7). Plus, I figured I'd notice if the softener was regenerating every night. It doesn't. So I'm pretty sure my pool is not over-taxing my softener.

The other possibility: that the auto-fill calls for water during the softener's regen cycle, in which case the softener's bypass valve would send hard water to the pool. To that I figure: "Oh well." My softener regen's in the middle of the night, so the chances of that are slim.

However hard water might make it to the pool: overtaxing, filling during regen, or during my "vacation mode," it is what it is. I seem to be able to flush out any excess CH during the rainy season, and the softener seems to keep up well enough during swim season. After three years, my CH is still below 400. For my pool/weather/use... it's working.

One quickie calculation you can perform (which now that I think about it, was how I double-checked all of Matt's math): I just looked at my water bill. My total water usage: house, pool and landscaping, everything, is less water usage than my softener's capacity. So subtracting out the landscaping (which is by far my biggest water consumer), there's no way I can out-use the softener.
 
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Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,208
Central California
I had two 1/4-turn shutoff valves installed - one before the softener and one after it so that I can either turn off the water to the softener, cutting off the house and the pool autofill line, or just turn off water to the house and leave the softener active along with the pool autofill line. That way, on vacations, the pool is still able to get water.
I considered that, but I have PEX, and it all runs through the attic, and that includes both the soft water circuit and my hose bib circuit (non-softened). Plus, I tapped my auto-fill line in the attic, not right by the softener, which further complicates things. Even if I hadn't, turning off after my softener would still leave active the non-softened circuit in the attic. Which is better than leaving everything active, true, but you know how Murphy's Law works! I'd have to go up there and find where the hose bib circuit branches off, and valve that somehow too. So I just shut it all off and put the pool on city water for the few days a year that's necessary, to be safest. As I mentioned above, whatever hard water makes it to the pool, I can deal with during rainy season.

I'm essentially doing mini no-drain exchanges using rain as the water source. Which I'd pretty much have to do anyway, even if CH didn't creep up, to manage salt build up. Collectively, the MO is working to minimize and probably eliminate ever having to drain my pool, even partially, which, for me, is the actual purpose of all this trouble!
 

JC707

Well-known member
Sep 5, 2020
127
Bay Area, CA
I was quite worried about this very thing myself, when I first converted the plumbing. Matt helped me calculate the expected amount of soft water used, and it was well below my softener's capacity (helped by the fact that I don't have a big family going at it 24/7). Plus, I figured I'd notice if the softener was regenerating every night. It doesn't. So I'm pretty sure my pool is not over-taxing my softener.

The other possibility: that the auto-fill calls for water during the softener's regen cycle, in which case the softener's bypass valve would send hard water to the pool. To that I figure: "Oh well." My softener regen's in the middle of the night, so the chances of that are slim.

However hard water might make it to the pool: overtaxing, filling during regen, or during my "vacation mode," it is what it is. I seem to be able to flush out any excess CH during the rainy season, and the softener seems to keep up well enough during swim season. After three years, my CH is still below 400. For my pool/weather/use... it's working.
This is great info I will keep in mind.

I normally have heard my regen cycle run around 3am. Should I manually adjust this to a different time?

My system was installed 2 years ago and it seems to have a bypass valve right before the softener. I will ask the technician when he comes for annual maintenance next week what my system's capacity is. We are a family of 5 with 3 young kids so laundry and dish washer is always running.
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,208
Central California
I added a paragraph to that post after you replied to it. Last paragraph might help.

I time my regen cycle so that I'm not likely going to use water inside during the regen cycle. I don't want any hard water in the interior circuit. While connecting the softener to the pool has been great, the primary purpose of my softener is to keep hard water out of my faucets and appliances and off my shower and toilet surfaces. For me, that takes precedence over the pool.

I'd say 3am is fine. For me it's a bit later, as I'm often still up at 3, so I go just before dawn. I have to be back in the coffin by then, so I don't use any water after that. 🧛‍♂️
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
17,378
Tucson, AZ
This is great info I will keep in mind.

I normally have heard my regen cycle run around 3am. Should I manually adjust this to a different time?

My system was installed 2 years ago and it seems to have a bypass valve right before the softener. I will ask the technician when he comes for annual maintenance next week what my system's capacity is. We are a family of 5 with 3 young kids so laundry and dish washer is always running.
2-3am is fairly normal. A full regen cycle takes 2-3 hours to complete and the valve goes into bypass mode when the softener is regenerating so you want that to happen when no one is using the water. Mine is set for 2am so it completes before 5am.
 

JC707

Well-known member
Sep 5, 2020
127
Bay Area, CA
I have 2 hose bibs available for when the time comes to fill the pool. The bib in backyard is tied into the softener system and bib out in front yard is on city water. I am guessing I can't fill the pool using the softener and just use the bypass valve on the softener? So I will have 2 hoses filling pool?
 

Dirk

Gold Supporter
TFP Guide
Nov 12, 2017
7,208
Central California
That sounds right. Even if your softener could keep up (it can't), you'd still want to use city water to get the CH your pool will need. You balance the CH at some point after the fill, and then only use soft water to make up the evaporation.
 
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