Insane CH increases -Help!

[spoonman]

Hi folks

I had reverse osmosis performed on my pool water in May of this year (2018). My water was 200CH after RO as confirmed by my test kit and the RO technician. As if today (October), a mere 5 months later, my water is measuring 700CH!

Sure, I live in Phoenix and have high levels of evaporation and high CH fill water. But at 700CH, that would assume I have lost 1.75x my pool water to evaporation over the summer. (200ch + 300 ch refill + .75x 300 ch refill = 700ch). Is this realistic?

I know Phoenix has high evaporation, but this seems higher than what I thought was lost to evap.

Any thoughts anyone??

 

[YippeeSkippy]

How are you chlorinating this pool? What do you use?

Do you have an auto-fill?

Maddie

 

[Texas Splash]

Can you confirm the year your pool was built? I see you have a stenner, so I doubt you've ever used Cal-Hypo correct? Not so sure about the formula used though. I'm no math major, but sometimes the added CH-to-existing CH ratio gets a bit tricky. Not so sure it's as easy as that. We have quite a few others from your local area who might be able to confirm seasonal changes to validate that though. In either case, you might want to consider supplementing refills from a water softener of possible. I myself have done that, and one of our experts Joyfullnoise from your area has also done the same and has a good thread of his own about it.

 

[spoonman]

How are you chlorinating this pool? What do you use?

Do you have an auto-fill?

Maddie

Hi Maddie,

I chlorinate strictly with liquid chlorine. An occasional puck for vacation. Never CalHypo. My pool doesn’t know what that is

 

[spoonman]

Can you confirm the year your pool was built? I see you have a stenner, so I doubt you've ever used Cal-Hypo correct? Not so sure about the formula used though. I'm no math major, but sometimes the added CH-to-existing CH ratio gets a bit tricky. Not so sure it's as easy as that. We have quite a few others from your local area who might be able to confirm seasonal changes to validate that though. In either case, you might want to consider supplementing refills from a water softener of possible. I myself have done that, and one of our experts Joyfullnoise from your area has also done the same and has a good thread of his own about it.

Hi Texas. My pool was built exactly 2 years ago. No cal hypo. When I had RO done earlier the CH was around 1350 after a year and a half, albeit probably lots of plaster residual in the water?

I do have an auto leveler, which is local tap. Just tested the tap which is around 250-300 depending on how violet/blue you go. Pool water is easily 700-750. I use a K-2006 but always feel the test is a bit subjective. Either way, I performed the tests in the same manner...going from pink to violet to slightly more blue.

 

[spoonman]

I was just reading about evaporation levels across the US. It seems the Phoenix area experiences around 100-110” a year. That equates to a bit over 9’ of water. Given that my average pool depth is roughly 4’, this seems to suggest that I lose just over 2x my pool’s water volume each year. Given that, it would stand to reason that I would lose 1.75x my water over the 5 months of Arizona summer.

Does this make sense? Seems logical if the evaporation rates and math add up.

 

[Texas Splash]

Does this make sense? Seems logical if the evaporation rates and math add up.

My brain refuses to work so hard on the weekend. However you are probably fairly close in your estimates. I'm sure one of our locals will collaborate on this thread soon.

Here's that thread I spoke of earlier: Water softener installation!!!!

 

[bdavis466]

Your math is correct and you are at a big disadvantage since the surface area is so large compared to your volume because the shallow depth.

I see a pool cover in your future...

 

[MyAZPool]

Hi folks

I had reverse osmosis performed on my pool water in May of this year (2018). My water was 200CH after RO as confirmed by my test kit and the RO technician. As if today (October), a mere 5 months later, my water is measuring 700CH!

Sure, I live in Phoenix and have high levels of evaporation and high CH fill water. But at 700CH, that would assume I have lost 1.75x my pool water to evaporation over the summer. (200ch + 300 ch refill + .75x 300 ch refill = 700ch). Is this realistic?

I know Phoenix has high evaporation, but this seems higher than what I thought was lost to evap.

Any thoughts anyone??

Spoonman,
I think your assumptions are correct based on my experiences here in Chandler. Our pool surface areas are similar (mine is 36x18).

I calculated (using two different methods) that I was losing approximately 80 gallons per day due to evaporation in late September (this really blew me away. I had no idea it was that much).

Before I started using soft water for backwash and evaporation compensation, my CH was also climbing very similar to yours.

It has seriously slowed down for me since converting from muni to soft water (200ppm vs 25ppm).

We are cursed in the desert with high water hardness.

Only 4 ways to deal with it, it appears.

1. More frequent backwash's.
2. Occasional partial drains.
3. Convert to soft water.
4. Pool cover.

Hope this helps to let you know, that what you are experiencing was also normal for my pool as well.

 

[mknauss]

Your evaporation is very reasonable. Our pool goes from 250 CH to 1000 CH in about 16 months.

Luckily, water is really cheap in Laughlin.

 

[peterl1365]

Hi Texas. My pool was built exactly 2 years ago. No cal hypo. When I had RO done earlier the CH was around 1350 after a year and a half, albeit probably lots of plaster residual in the water?

I had high CH levels 600-1000ppm for the first 5-6 years after my pool was built. I did partial drains every couple of years or so to knock it down to 400 or so temporarily, but the CH just kept climbing. I also have white plaster.

Then, in the last 3-4 years, the CH began to stabilize around 400-500 without any significant action on my part. I don't know if it was because the plaster finally found a good equilibrium, or my water district started supplying softer water, but I haven't had to worry about CH since then. Last I checked, it was sub-400.

Anyway, that was a long winded way of saying that reducing the CH to 200 through R/O might have had the unintended consequence of leaching some additional calcium out of your plaster. You may want to be satisfied with CH levels around 500 or so for a few years. I found that as long as I kept my PH under control, the high CH was not really a factor. I had some scale buildup (probably unavoidable in a desert climate) along the water line that I've had to clean up twice in 10 years, but that's about the worst of it.

 

[spoonman]

Your evaporation is very reasonable. Our pool goes from 250 CH to 1000 CH in about 16 months.

Luckily, water is really cheap in Laughlin.

mknauss I believe Laughlin is one of the few places hotter (and drier) than Phoenix. In Phoenix we get more monsoonal activity in the summer, which helps somewhat. I believe Laughlin is the hottest part of the desert (albeit marginally), followed by the Coachella Valley.

- - - Updated - - -

Your math is correct and you are at a big disadvantage since the surface area is so large compared to your volume because the shallow depth.

I see a pool cover in your future...

I have a pool cover that I use in the shoulder season (mostly spring). Don't like using all the time because in the summer it gets the pool too hot...plus I like looking at the water. Trade-offs I guess.

 

[spoonman]

Spoonman,
I think your assumptions are correct based on my experiences here in Chandler. Our pool surface areas are similar (mine is 36x18).

I calculated (using two different methods) that I was losing approximately 80 gallons per day due to evaporation in late September (this really blew me away. I had no idea it was that much).

Before I started using soft water for backwash and evaporation compensation, my CH was also climbing very similar to yours.

It has seriously slowed down for me since converting from muni to soft water (200ppm vs 25ppm).

We are cursed in the desert with high water hardness.

Only 4 ways to deal with it, it appears.

1. More frequent backwash's.
2. Occasional partial drains.
3. Convert to soft water.
4. Pool cover.

Hope this helps to let you know, that what you are experiencing was also normal for my pool as well.

Always good to hear from fellow desert dwellers. I think the list you provided pretty much sums up the options. I've come to realize that a softener is probably the way to go, just need to do it among competing priorities like possibly adding a SWG. The evaporation rates are pretty stunning and I don't like wasting water more than necessary (using the cover more could help too, but that would beat up my cover more in the sun ). I crunched the math and it seems that a softener would save a bit of water (despite regen cycles) compared to draining the pool every 2 years (which is the current path).

 

[Dirk]

I've never actually decided the amount of money it is worth to me not to have to deal with replacing water due to rising CH; or looking at and/or removing scale on my tile, pool surfaces or SWG. But I can tell you it's no where near the amount I spent on a softener and its salt. And since I really bought the softener for my indoor fixtures and shower glass (well before I thought to connect it to my pool), it really only comes down to the added expense of the increase use of softener salt due to my pool's evaporation (which is similar to yours). A very rough estimate for the salt the softener needed to fill the pool this past swim season... maybe $20? $30 tops? How much tile are you willing to scrub for $30?

I can't find a spec of scale in my pool after an entire summer with the softener. When I bought the house (previous owners had no softener), the entire pool and all the tile were covered in it (not to mention the toilets). Proof enough for me...

The mystery I can't quite solve? I still get a little ring of scale in the toilets every few months. And there should be some on the pool tile, because of the nature of evaporation. There just isn't!

 

[Dirk]

Spoonman, I was writing as you were posting about your calc's. To be fair, you have to consider that a softener will not eliminate completely the need to replace water. Your pool is accumulating salt, with or without an SWG. We'll eventually have to deal with that. So water replacement is in our future. I haven't done the math yet, I'm pretty sure the rate to replace due to salt build up is less than CH build up, but that would be different for every pool, I suppose...

 

[spoonman]

^Wonder if your toilet scale is from the porcelain in the toilet's tank? Usually the inside of the tank is not glazed. Presumably this could leech into the water?

Dirk, I have a softener loop in may garage. If I connected a softener to this, is it likely that the hose bib in my backyard (connected to the auto leveler) would get soft water? I'd hate to have to trench up my backyard to run a soft line.

 

[Dirk]

If your house was plumbed correctly your hose bibs would definitely not be soft water. There should be two independent systems in your house: exterior on one loop, interior on the other. (Sometimes there is a hard water valve under the kitchen sink.)

I have a thread that describes my process, and yes, there was some trenching. I lucked out in that my autofill supply line ran right by my pool pad, so I didn't have to do much. I found the soft water loop in the attic, and spliced in a run of PEX from there to a new hose bib near the pad, which I then connected to the auto fill. It wasn't too bad. The bib doubles as my soft water supply for hosing off the PV panels and washing the car. A three-fer!

Here (though the thread is convoluted with many of my newbie questions and experiences):

Water softener connected to auto fill, and new plaster start up.

 

[Dirk]

Later on in that thread I also explore rain water filling to control CH. I've been through it all!!

There's also some info in there about proper back flow prevention when you connect a pool to your drinking water plumbing...

 

[spoonman]

Uh oh, having to tap into a soft line inside the house and create a plumbing run to my pool pad sounds expensive. I can't think of any soft water line running along the pool pad side of my house. I also have a 2 story to make things more complicated. Thanks for posting your thread. I'll give it a read. Maybe it will give me some hope!

 

[Dirk]

Well, I had just finished replacing an entire fourplex's plumbing system with PEX, so I had what I needed to do it myself. Probably cost me all of $20. A plumber would not be cheap, for sure. But there could be a shortcut. Got any sinks that back up to an exterior wall? Does the kitchen look out to the back yard? Or is a bathroom or laundry room sink on the opposite side of a backyard wall? It wouldn't take much to open up the sheetrock under the sink, punch a hole through the siding, and connect up a hose bib to the existing cold water line feeding the sink (or washing machine). My easiest access just happened to be in my one-story attic, which is very tall inside. Yours might be a sink or toilet on the ground floor. Pretty much anything with cold water running to it...

Just checking: you mentioned the autofill source as a hose bib. That's where you need to get to, not the pad. Unless they are in the same place.

Sidebar: I managed to lose a little weight diggin' up my yard for the soft water line and the solar pipes! Not that you don't look fantastic or anything. Just sayin'... we could all use a little exercise, right?