Question on my CH

spinPHD

Well-known member
Apr 20, 2017
500
Phoenix
I just drained and refilled my pool two weeks ago due to high CYA and CH. As most of you know, Arizona is notorious for its high CH in our fill water so it can creep up pretty high after a few years.

In any event, after the refill my CH was 150. I know the recommended range starts at 200, but I was wondering if 150 is fine for me since it will naturally raise over time or do you think I should still raise my calcium?

I know my CSI is what I need to watch out for with low (and high) CH, but also that my PH plays a bigger role in CSI than any other factor. If I maintain higher range of PH (7.6-7.8) to keep CSI in check until CH goes up naturally, will that work? I would ultimately like to lower my TA, but would hold off on doing that for now, since that requires lowering ph to the low 7s with muriatic acid. Doing that would put my CSI too close to -0.6

Here is my latest test as of this morning:
FC: 7.2
CC: 0
PH: 7.7
TA: 120
CH:150
CYA: 40
Water Temp: 80
 

spinPHD

Well-known member
Apr 20, 2017
500
Phoenix
IMO you would be best served to drop the TA to ~60 and get the CH to > 200. Plug those into Pool Math and see what you think.
I agree with you on those numbers, and I've been working to get my TA down. It started at 150 after the fill and slowly been lowering it. It takes a long time because you need to keep ph in check while adding muriatic acid.

However, in AZ it's not uncommon for people to drain pool ever 2 years or so due to CH creeping over 1000. I just figured that adding calcium with our water conditions and evaporation rates would be a waste of money, when I will be faced with too high of CH anyway in near future.
 

Richard320

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Jan 6, 2010
20,406
San Dimas, CA (LA County)
If I was in your shoes, I'd do exactly what you propose. I, too, suffer from hard water and rapid CH climb, to the tune of about 25/week in the summer. It won't be long before you have to worry about keeping pH and TA down. I know that's below the recommendations for the pebbletec, but it won't be for very long, and you are watching CSI.
 

duraleigh

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I agree with 320.....do what you plan to do.....that'll work.

changing the subject ever so slightly, have you considered a softener? Does it make economic sense in AZ?
 

spinPHD

Well-known member
Apr 20, 2017
500
Phoenix
I agree with 320.....do what you plan to do.....that'll work.

changing the subject ever so slightly, have you considered a softener? Does it make economic sense in AZ?

I've lived in AZ for 18 years, and of the half a dozen places I've lived they never had a softener. In fact, I never really thought they were "a thing" here until I started looking at homes earlier this year and noticed a few houses with them. Now that I am first time homeowner with a pool, it might be worth checking into.

I may be in large minority though, but whenever I visit the in laws in Iowa who have a water softener the water feels strange to me. Almost like it's slimy, but it's probably because I'm so use to the hard water here.
 

Richard320

TFP Expert
LifeTime Supporter
Jan 6, 2010
20,406
San Dimas, CA (LA County)
I've lived in AZ for 18 years, and of the half a dozen places I've lived they never had a softener. In fact, I never really thought they were "a thing" here until I started looking at homes earlier this year and noticed a few houses with them. Now that I am first time homeowner with a pool, it might be worth checking into.

I may be in large minority though, but whenever I visit the in laws in Iowa who have a water softener the water feels strange to me. Almost like it's slimy, but it's probably because I'm so use to the hard water here.
I'm with you there. Soft water tastes funny, and it never feels like you've rinsed completely clean in the shower.
 

JoyfulNoise

TFP Expert
Platinum Supporter
May 23, 2015
14,874
Tucson, AZ
Ion exchange based water softeners CAN work here in Arizona, but you have to get an outdoor model that's hooked up to your fill line (if you have an auto fill) and dedicated to the pool. Also, you can only use it for topping off, not filling a pool. The reason why you want a dedicated unit is because the summer evaporation rates are really high and the softener will run A LOT. If you tie your autofill into the water softener that is supplying your home, you can easily have multiple regeneration cycles occur in a day and, once in regenerating mode, the rest of the house will be hit with regular water from the bypass valve. When regenerating, a water softener can use as much as 100 gallons of water to flush out the resin bed. So, if you start regenerating a lot, you'll basically just be pouring a lot of extra water down the drain. Therefore it's best to keep the household softener and the pool softener separate.

One of these days I'll get myself a softener, there's always just other higher priority items that keep cropping up.

Oh, and for reference, my CH is currently sitting at 1100ppm and I'm totally able to keep my water balanced and clear.
 

CaptainCannonball

Silver Supporter
May 18, 2016
240
Woodland, Ca
I think it's all about proper sizing when it comes to softeners, our model is set to provide 5800 gallons in between regenerations and uses nowhere near 100 gallons to regenerate. Winter we typically reach the time cutoff for regeneration (12 days) and admittedly we don't have near the evap concerns of AZ, but we keep a warm pool here in the summer and have about weekly regenerations.
 

spinPHD

Well-known member
Apr 20, 2017
500
Phoenix
Ion exchange based water softeners CAN work here in Arizona, but you have to get an outdoor model that's hooked up to your fill line (if you have an auto fill) and dedicated to the pool. Also, you can only use it for topping off, not filling a pool. The reason why you want a dedicated unit is because the summer evaporation rates are really high and the softener will run A LOT. If you tie your autofill into the water softener that is supplying your home, you can easily have multiple regeneration cycles occur in a day and, once in regenerating mode, the rest of the house will be hit with regular water from the bypass valve. When regenerating, a water softener can use as much as 100 gallons of water to flush out the resin bed. So, if you start regenerating a lot, you'll basically just be pouring a lot of extra water down the drain. Therefore it's best to keep the household softener and the pool softener separate.

One of these days I'll get myself a softener, there's always just other higher priority items that keep cropping up.

Oh, and for reference, my CH is currently sitting at 1100ppm and I'm totally able to keep my water balanced and clear.
Out of curiosity Joyful, how long did it take you to get your CH to that level? Also, what do you keep your PH and TA at for that high of CH?
 

triptyx

TFP Guide
Apr 12, 2016
1,495
Tucson, AZ
I refilled last April with 200ppm CH fill, and am already at 500ppm last weekend when I tested.

It goes up very fast here.
 

JoyfulNoise

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May 23, 2015
14,874
Tucson, AZ
Out of curiosity Joyful, how long did it take you to get your CH to that level? Also, what do you keep your PH and TA at for that high of CH?
The water is going on 4 years old. Like triptyx, my water started at nearly 300ppm (municipal water here is about 280ppm on average) and it has gone up anywhere from 250-300ppm per year.

Here's why - Class A pan evaporation rates in Tucson (as measured by two sites operated by UofA....BEAR DOWN/GO WILDCATS!!!) show an annual evaporation of 90" or more per year (been that way for decades). So, since a lot of pools are, on average, 5-6 ft deep, you are basically evaporating an entire pool volume away in one year when the pool is uncovered. So, whatever your municipal water hardness is, that is about how much you can expect your CH to increase by in one year.

Kinda stinks, huh??

My plan is that I'll probably drain my pool this fall (I'm considering doing a Zero Alkalinity treatment first to "freshen up" the plaster surface as well as get my tiles blasted), power wash the plaster surface and then refill. Unfortunately that's going to cost me 12 bags of salt, another 50lbs bucket of boric acid and about 16CCF of water (~$200-$300)...but that's the price you pay for living in this desert paradise....
 

spinPHD

Well-known member
Apr 20, 2017
500
Phoenix
The water is going on 4 years old. Like triptyx, my water started at nearly 300ppm (municipal water here is about 280ppm on average) and it has gone up anywhere from 250-300ppm per year.

Here's why - Class A pan evaporation rates in Tucson (as measured by two sites operated by UofA....BEAR DOWN/GO WILDCATS!!!) show an annual evaporation of 90" or more per year (been that way for decades). So, since a lot of pools are, on average, 5-6 ft deep, you are basically evaporating an entire pool volume away in one year when the pool is uncovered. So, whatever your municipal water hardness is, that is about how much you can expect your CH to increase by in one year.

Kinda stinks, huh??

My plan is that I'll probably drain my pool this fall (I'm considering doing a Zero Alkalinity treatment first to "freshen up" the plaster surface as well as get my tiles blasted), power wash the plaster surface and then refill. Unfortunately that's going to cost me 12 bags of salt, another 50lbs bucket of boric acid and about 16CCF of water (~$200-$300)...but that's the price you pay for living in this desert paradise....
You're asking a Sun Devil alumni to trust numbers that come from Wildcat website? I've heard that if you drive slow enough down Speedway they give you a degree from UofA? haha.

Kidding aside, thank you for info. It does give me a good idea of what to expect. I actually turned my auto fill off this morning just so I can physically see how much evaporation I can expect in a day over 100 degrees.
 

JoyfulNoise

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May 23, 2015
14,874
Tucson, AZ
You're asking a Sun Devil alumni to trust numbers that come from Wildcat website? I've heard that if you drive slow enough down Speedway they give you a degree from UofA? haha.

Kidding aside, thank you for info. It does give me a good idea of what to expect. I actually turned my auto fill off this morning just so I can physically see how much evaporation I can expect in a day over 100 degrees.
Expect anywhere between 1/4" and 1/2". One of our veteran experts devised quite an apparatus for doing a bucket-test evaporation measurement....used orange HD buckets, plywood and screw/dial depth indicators....all very "high tech".

Hahahaha....no, the only thing you ever get driving down Speedway are traffic tickets!! The Tucson Police consider Speedway their primary source of funding for their pensions....(hahah, just kidding, I love the Tucson PD!!)

How do you keep an ASU SunDevil out of your driveway? Just put up a basketball net :laughblue:
 

duraleigh

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Apr 1, 2007
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I am trying very hard to be quite about our 50 inches of rainfall annually
 

CaptainCannonball

Silver Supporter
May 18, 2016
240
Woodland, Ca
I've lived in AZ for 18 years, and of the half a dozen places I've lived they never had a softener. In fact, I never really thought they were "a thing" here until I started looking at homes earlier this year and noticed a few houses with them. Now that I am first time homeowner with a pool, it might be worth checking into.

I may be in large minority though, but whenever I visit the in laws in Iowa who have a water softener the water feels strange to me. Almost like it's slimy, but it's probably because I'm so use to the hard water here.
I used to feel that way about soft water until I found out that the "squeaky clean feeling" was actually my soap forming a curd with the calcium in the water. I had no idea about them until we bought a house with one and did the research, now it is a luxury I'm not willing to live without. I think my pool likes it too, our last pool I always had to counter high calcium with lower than I liked Ph. I use much less acid now as a side benefit. YMMV :)

- - - Updated - - -

Love the Alumni jokes... Always liked the one that goes: How do you get a "insert rival alumni school" grad off your lawn? Pay him for the pizza :)
 

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