Calcium Hardness decreasing

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MyAZPool

MyAZPool

Gold Supporter
Jul 3, 2018
2,296
Arizona
Pool Size
20500
Surface
Plaster
Chlorine
Salt Water Generator
SWG Type
Pentair Intellichlor IC-60
Marty
Question for you sir if you wouldn't mind.
So CH is gradually decreasing ever since I converted to soft water (nearly a year ago). So far, so good. Just what I wanted to happen.
However, my CH is now at 400ppm and there is no doubt that it will continue it's downward trend over time.

With a pebbletec finish/salt pool, at what point (CH level) would you recommend that I halt this downward trend and start adding city water (250ppm) versus the soft water (25ppm)?

Your help, opinions and experience are greatly appreciated.
Thanks
r.
 
I’m not Marty but I’m better looking ....

What’s you CSI saying. You can manage your pool’s CSI by tweaking pH and TA and pretty much let the CH do whatever it wants. I wouldn’t intervene until the CH gets near 200ppm.

FYI, I’m still at 900ppm CH which is down from 1500ppm before the softener install. I’d love to get to 400. I plan to do some heavy draining this fall.
 
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mknauss said:
Manage your CSI. Keep it between -0.3 and 0.
Click to expand...
Got it.
JoyfulNoise said:
I’m not Marty but I’m better looking ....
What’s you CSI saying. You can manage your pool’s CSI by tweaking pH and TA and pretty much let the CH do whatever it wants. I wouldn’t intervene until the CH gets near 200ppm.
FYI, I’m still at 900ppm CH which is down from 1500ppm before the softener install. I’d love to get to 400. I plan to do some heavy draining this fall.
Click to expand...
Marty and Matt
:laughblue:Matt, too funny but Marty might disagree lol...

CSI is currently at -0.19. Below is a screenshot of my latest pool math. Yea, I started pool refill with soft water (CH of 25), when the pool CH was about 800ppm I believe, so that's about right.
I'll continue to let it down a bit more. I just don't want it to get too low. I would rather try to keep it right at an optimum (target) number, since it is very easy for me to just shut the soft water valve off and turn the city water valve on which leads to the auto refill. Any optimum (target) number that you could advise would be helpful (I know the range value of 350 to 450).
Here are my present numbers if that helps.
110907

ps. Matt, I plan to respond to your post in that IntelliChlor thread just as soon as I can gather up a bit more info in order to respond.

Thank you both!! I am always very appreciative of your excellent help!
r.
 
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Matt,
Okay, right now the great City of Chandler Municipal water (before softening) is:
pH 7.6
TA 110
CH 150 - But I believe this to be somewhat of an anomaly, since I have tested it several times in the past and it's always been around 250.

The softened water (which is currently the pool refill water) is:
pH 7.5
TA 90
CH 25
Thanks Matt!
r.
 

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So here’s the deal as to why I asked. In arid climates we tend to play a game with our fill water and pool water where we just let the CH do whatever it wants and then adjust TA and pH to get the CSI where we want. The problem is, when the TA of your fill water is far away from the TA of the pool water, then that adds to the upward pressure on pH rise since you’re always fighting to keep your TA lower than what it naturally wants to be.

So I would say that your “optimal” CH target is one that allows your TA and pH to be as close to your fill water TA and pH. At a CH of 250, you can easily let your TA rise to 100ppm (closer to your natural fill water) and let your pH live between 7.6-7.8, and your CSI will be fine. Then, because you are adding water to your pool that’s chemically very similar to the pool water, the pH should need less adjusting with acid as long as you keep your sources of aeration minimal (aside from letting swimmers have fun).
 
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JoyfulNoise said:
So here’s the deal as to why I asked. In arid climates we tend to play a game with our fill water and pool water where we just let the CH do whatever it wants and then adjust TA and pH to get the CSI where we want. The problem is, when the TA of your fill water is far away from the TA of the pool water, then that adds to the upward pressure on pH rise since you’re always fighting to keep your TA lower than what it naturally wants to be.

So I would say that your “optimal” CH target is one that allows your TA and pH to be as close to your fill water TA and pH. At a CH of 250, you can easily let your TA rise to 100ppm (closer to your natural fill water) and let your pH live between 7.6-7.8, and your CSI will be fine. Then, because you are adding water to your pool that’s chemically very similar to the pool water, the pH should need less adjusting with acid as long as you keep your sources of aeration minimal (aside from letting swimmers have fun).
Click to expand...
Matt,
I think I get where you are coming from with your explanation and yes, I do experience just what you detailed in the first paragraph.

Just to be clear, I will continue with the soft water refill and allow my CH to continue to decrease down to 250. And then just allow my TA to rise closer to 100ppm while continuing to keep my pH value around 7.7 (which is where I let my pH live now) and then my CSI will still continue to be fine.

Hopefully, MA consumption will decrease a bit (in the hot summer months I consume about 1 gallon of MA per month (ipH at 65%/pump daily run time of 11.5 hrs).
Thank you very much for the detailed explanation and I will be sure to implement your advice.
Take care and try to stay cool down there to the south. Thanks again!!!
r.
 
duraleigh said:
Not sure what you mean. Certainly there is a VERY wide operating range with 250-400 seeming the most widely accepted as a "good" value. What does 350-450 mean?
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Dave,
Sorry, I originally got that number from Pool Math.

110916

But now I see that I can continue to allow my CH to decrease a bit more, closer to it's natural value of 250.
Take care and thanks!
r.
 
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I keep 4 gallons of MA on hand (eKonomy Pools sells it in refillable 4 ups with a safety carrier) and I go through approx 8-10 gallons of MA per year. So I know what you mean. I’ve often thought of getting a dosing system to automate acid demand but that’s a project for another day. iPH would integrate with my EasyTouch pretty easily.

It’s going to rain down here soon so the monsoon season has started. We’ll be seeing cooler weather for the next few weeks.
 
JoyfulNoise said:
I keep 4 gallons of MA on hand (eKonomy Pools sells it in refillable 4 ups with a safety carrier) and I go through approx 8-10 gallons of MA per year. So I know what you mean. I’ve often thought of getting a dosing system to automate acid demand but that’s a project for another day. iPH would integrate with my EasyTouch pretty easily.

It’s going to rain down here soon so the monsoon season has started. We’ll be seeing cooler weather for the next few weeks.
Click to expand...
Matt
Yea, so far I am pretty pleased with the IntellipH. Working as advertised and integrates with the IntelliChlor and the automation just fine. I only wish that Pentair would release an update (that they are supposed to) that would allow total ipH integration (control) with my automation. But that's another story for another time (thread). :)

Now I just need to get a device that measures pool water CH and sends that data to a device that would control valve actuators to control whether the pool refill valve gets fed hard water (CH-250) or soft water (CH-25). NO NO NO NO NO NO NO....:sick: I really need to stop trying to see just how much of that pool that I can automate. :p. Last time I got a bright idea like that, I got hammered for totally digging up the wife's rose garden in order to install the plumbing for the refill line hard/soft water selection valves and install a digital water metering device that sends the data to the equipment pad that registers pool water refill consumption. Where will it all end? :rolleyes:

110923 110924

Wish we would get some of your rain.
Thanks again and take care...
r.
 
Nice setup.

If you want to cool off you’re welcome to come down here and install a cross-connect between my city water and softener supply lines to the pool auto fill. It’s actually fairly easy to do with no digging required, I’m just lazy enough to not get it done ?
 
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Matt
Based on our discussions here regarding borates (yea, guess we got a little "off-topic" :)), and this article
Click to expand...
and also on your excellent write-up here:

New borate drop test at piscines-apollo vs. test strip

Thanks, SunnyBlues. You have been reading and learning a LONG time to remember all those experts. Thanks for your testimonial.
www.troublefreepool.com www.troublefreepool.com
Click to expand...
I have decided to bump my borates up a bit to about 80ppm and use the borate drop test instead of the LaMotte test strips.

My question is this. Is all of the information (to include the materials necessary and procedures) provided in your write-up still current and valid?
Thanks very much!
r.
 
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