3 months after plaster going through 13 oz of acid a day, normal?

[QingGuy]

Called my local pool supply store to find out what sizes they sold calcium chloride in and the guy told me they don't carry it here due to the hardness of the water. Then proceeded to tell me how I was crazy (not in those exact words) to want to raise the hardness in my water here. Didn't even go into pool math etc. with him.

So if the local pool store doesn't carry calcium chloride who would?

 

[otter86753]

Like you, I live in an area where we do not get ice so de-icer is not an option for the product. I found this company and they shipped to my door Calcium Chloride Anhydrous - ChemistryStore.com

Best of luck,

 

[QingGuy]

Like you, I live in an area where we do not get ice so de-icer is not an option for the product. I found this company and they shipped to my door Calcium Chloride Anhydrous - ChemistryStore.com

Best of luck,

Thanks, I posted on a local neighborhood website to see if anyone has a local source as I'd like to get some in my pool asap as my CSI is sitting at -.83, if not I'll order from them. Thanks again!

 

[otter86753]

A quick search in your area brought up this company Chemical Lime Company | Las Vegas, NV - Macrae's Blue Book

 

[otter86753]

If that doesn't help, here is Grainger in Las Vegas
LAS VEGAS Branch #423
2401 Western Ave..,
LAS VEGAS, NV 89102-4815
2.25 mi
Phone & HoursDriving Directions
Phone
(702) 385-6833
Fax
(702) 387-0278
Hours
Monday - Friday 7:00 AM - 4:30 PM PACIFIC

 

[QingGuy]

Found some at Walmart, the HTH product. Called one of the above and they only sell in large volumes. Thanks for the help guys!

Still a little nervous about raising hardness when our water is already so hard but I believe in the TFP method so here we go!

 

[bdavis466]

If you are concerned with your CSI, I would not add calcium, just raise your TA and pH to get it up to an acceptable range and just deal with adding acid a little more frequently than you would with a lower TA.

Once you dump the calcium in, you can't take it out and if you don't get a good amount of rain (I can't see your location on my phone) your CH will be steadily rising anyway. TA and pH are easily lowered when the time comes.

Again, this only applies if you expect your CH to rise with time

 

[JoyfulNoise]

If you are concerned with your CSI, I would raise your TA and pH to get it up to an acceptable range and just deal with adding acid a little more frequently than you would with a lower TA.

Once you dump the calcium in, you can't take it out and if you don't get a good amount of rain (I can't see your location on my phone) your CH will be steadily rising anyway

^^^^^^^+1

Totally agree with that. Being in NV your CH fill is high enough that you do not need to waste money on calcium products.

Just raise your pH and TA to increase your CSI.




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[bdavis466]

I wish I was smart enough to do that on my own pool. I voluntarily raised the CH to 400 from 125.... I'm at 650 now. I had no idea it would rise as fast as it has. I'll probably be at 675 by the time I finish typing this

 

[QingGuy]

If you are concerned with your CSI, I would not add calcium, just raise your TA and pH to get it up to an acceptable range and just deal with adding acid a little more frequently than you would with a lower TA.

Once you dump the calcium in, you can't take it out and if you don't get a good amount of rain (I can't see your location on my phone) your CH will be steadily rising anyway. TA and pH are easily lowered when the time comes.

Again, this only applies if you expect your CH to rise with time

^^^^^^^+1

Totally agree with that. Being in NV your CH fill is high enough that you do not need to waste money on calcium products.

Just raise your pH and TA to increase your CSI.

I'm in Vegas

Please don't take this wrong but now I'm totally confused. Addressing my initial topic I was instructed to lower my TA to recommended levels http://www.troublefreepool.com/content/134-recommended-levels, now you're thinking I should raise my TA?

 

[JoyfulNoise]

Tell you what, the topic has wandered a bit. Why don't you post your latest test results?

You mentioned a really low CSI for some reason, did you drop your pH again to reduce TA? If so, don't worry about CSI, it's temporarily negative because of the low pH. It won't stay that way and a brief exposure to low CSI will not damage anything. There is no need to raise CH to compensate.

 

[bdavis466]

I'm saying target a CSI value instead of the recommended individual pH and TA numbers until your CH rises. If you want to add less acid, then yes, lower the TA and raise the CH.

I am just trying to help you save money on calcium chloride and an eventual water replacement.... this is going to come at the cost of acid though.

Regardless of what you do, you will always be adding lots of acid very frequently. It seems recently everyone is under the impression that once your TA drops to 50, you will not have to add any acid. That may be the case with a vinyl pool in a region with good fill water and rainfall, but that is not the case for you and I (and Matt).

Your priority now should be protecting your plaster. The only way to do that without raising your CH (and it will on its own) is to keep your TA slightly higher for the time being. This will add a little effort now but will save you in the future.

- - - Updated - - -

Tell you what, the topic has wandered a bit. Why don't you post your latest test results?

You mentioned a really low CSI for some reason, did you drop your pH again to reduce TA? If so, don't worry about CSI, it's temporarily negative because of the low pH. It won't stay that way and a brief exposure to low CSI will not damage anything. There is no need to raise CH to compensate.

Indeed, current numbers would be very helpful.

 

[chem geek]

Is this your water quality report? If so, it says the following:

Las Vegas Valley Water District water is considered “very hard”—like many Western cities’ water supplies. Hardness is about 290 parts per million (ppm) or 17 grains per gallon.

Now that is referring to Total Hardness which would include magnesium, but calcium hardness is often around 70% of total hardness so that would make the CH of the fill water around 200 ppm, though you reported 290 ppm but that's 3 months after an initial fill and with plaster curing. If your pool is not covered, then evaporation and refill will add whatever is in the fill water to your pool. As shown in this pan evaporation map, Las Vegas has high annual evaporation rates of around 120" per year. I'm trying to figure out your pool's average depth and it doesn't make sense since 28,000 gallons with a 38'x31' surface implies an average depth of only 3.2 feet. If your shallow end is 3 feet and deep end 6 feet then average pool depth would be more like 4.5 feet so something isn't adding up. You wrote you have a 110' perimeter, so are you sure the "38" isn't really "28" since that would give a perimeter of 118'.

Anyway, if I just assume a 4.5' pool depth then with 120" evaporation and refill your CH would climb by ((120/12)/4.5)*200 = 444 ppm per year which is substantial and will require water dilution on an ongoing basis or replacement every couple of years or so. Given this, I agree with the advice on NOT raising your CH level since it is much harder to lower the CH level since that requires water dilution/replacement. So instead of trying to maintain a lower TA level to reduce the rate of pH rise, you can just do that to a limited extent that has your water chemistry (CSI) balance out targeting a higher pH of around 7.7 to 7.8 assuming you don't have significant metals (i.e. iron) in your water. Note that your water quality report notes copper levels of 0.1 to 1.1 with 90th percentile of 0.7 so I wouldn't have your pH get to 8.0 or higher if you can help it. So add acid to get to 7.5, let your pH rise to 7.7 or 7.8, and the TA will get higher with evaporation and refill as well. Over time if the TA gets so high that the CSI is higher, you can lower your pH target and that will use more acid which will counteract the TA rise.

It would be helpful to us if you could measure the pH, TA, and CH of your tap/fill water. That will help us predict your situation a little better, though the essence of it is as I described.

 

[Agent99]

If you play with pH in Pool Math, you'll see it, by far, has the largest impact on CSI.

 

[QingGuy]

Thanks for all the comments, will read them now, wanted to quickly post current numbers.

FC 4
CC 0 - .5
pH 7.2
TA 70
CH 290
CYA 70
CSI - -0.83

 

[QingGuy]

Tell you what, the topic has wandered a bit. Why don't you post your latest test results?

You mentioned a really low CSI for some reason, did you drop your pH again to reduce TA? If so, don't worry about CSI, it's temporarily negative because of the low pH. It won't stay that way and a brief exposure to low CSI will not damage anything. There is no need to raise CH to compensate.

Only reason I mentioned CSI was after updating pool math it flashed something about plaster corrosion and scared the &%#@ out of me LOL.

I'm saying target a CSI value instead of the recommended individual pH and TA numbers until your CH rises. If you want to add less acid, then yes, lower the TA and raise the CH.

I am just trying to help you save money on calcium chloride and an eventual water replacement.... this is going to come at the cost of acid though.

Regardless of what you do, you will always be adding lots of acid very frequently. It seems recently everyone is under the impression that once your TA drops to 50, you will not have to add any acid. That may be the case with a vinyl pool in a region with good fill water and rainfall, but that is not the case for you and I (and Matt).

Your priority now should be protecting your plaster. The only way to do that without raising your CH (and it will on its own) is to keep your TA slightly higher for the time being. This will add a little effort now but will save you in the future.

- - - Updated - - -

Indeed, current numbers would be very helpful.

Understand and appreciate it I truly do. Initially I was posting just as a check on whether or not my acid use was normal. Then it was pointed out that my TA was high based on recommended levels for SWG/plaster pools, then I realized I that when I turned on my SWG I updated the CYA figure but neglected to update the TA and CH targets so I was trying to get in-line with recommended levels.

Is this your water quality report? If so, it says the following:

Now that is referring to Total Hardness which would include magnesium, but calcium hardness is often around 70% of total hardness so that would make the CH of the fill water around 200 ppm, though you reported 290 ppm but that's 3 months after an initial fill and with plaster curing. If your pool is not covered, then evaporation and refill will add whatever is in the fill water to your pool. As shown in this pan evaporation map, Las Vegas has high annual evaporation rates of around 120" per year. I'm trying to figure out your pool's average depth and it doesn't make sense since 28,000 gallons with a 38'x31' surface implies an average depth of only 3.2 feet. If your shallow end is 3 feet and deep end 6 feet then average pool depth would be more like 4.5 feet so something isn't adding up. You wrote you have a 110' perimeter, so are you sure the "38" isn't really "28" since that would give a perimeter of 118'.

Anyway, if I just assume a 4.5' pool depth then with 120" evaporation and refill your CH would climb by ((120/12)/4.5)*200 = 444 ppm per year which is substantial and will require water dilution on an ongoing basis or replacement every couple of years or so. Given this, I agree with the advice on NOT raising your CH level since it is much harder to lower the CH level since that requires water dilution/replacement. So instead of trying to maintain a lower TA level to reduce the rate of pH rise, you can just do that to a limited extent that has your water chemistry (CSI) balance out targeting a higher pH of around 7.7 to 7.8 assuming you don't have significant metals (i.e. iron) in your water. Note that your water quality report notes copper levels of 0.1 to 1.1 with 90th percentile of 0.7 so I wouldn't have your pH get to 8.0 or higher if you can help it. So add acid to get to 7.5, let your pH rise to 7.7 or 7.8, and the TA will get higher with evaporation and refill as well. Over time if the TA gets so high that the CSI is higher, you can lower your pH target and that will use more acid which will counteract the TA rise.

It would be helpful to us if you could measure the pH, TA, and CH of your tap/fill water. That will help us predict your situation a little better, though the essence of it is as I described.

Pool is not covered. Shallow end is 3.5', deep 7', and perimeter 110' (personally confirmed). The 38' might be pre-shotcrete so it could be 36" but I don't think so as the excavator told me he moved it out two feet. 100% confident it's not 28'

At lunch I'll get the numbers from water at the hose bib, I have a water softener and RO in the house.

If you play with pH in Pool Math, you'll see it, by far, has the largest impact on CSI.

Noticed that.

Thanks again to everyone who is contributing, I greatly appreciate it :bowdown:

 

[JoyfulNoise]

Thanks for all the comments, will read them now, wanted to quickly post current numbers.

FC 4
CC 0 - .5
pH 7.2
TA 70
CH 290
CYA 70
CSI - -0.83

Aerate back up to 7.8 and you'll be fine. Drop your pH no lower than 7.6 and see how the stability goes. The entire point of this thread was to get you a more stable pH. So leave your numbers where they are and look to target a pH range of 7.6-7.8. I noticed you did not list salt levels, that number does change the CSI a bit so please include whatever your most recent salt level is.

As for CH, your fill water is going to raise it slowly. If you really want it higher in a shorter period of time you could add calcium to bring your water up to 300ppm, but it really isn't necessary. My annual increases in CH are measured in 100's of ppm and our fill waters are very similar.

 

[QingGuy]

Aerate back up to 7.8 and you'll be fine. Drop your pH no lower than 7.6 and see how the stability goes. The entire point of this thread was to get you a more stable pH. So leave your numbers where they are and look to target a pH range of 7.6-7.8. I noticed you did not list salt levels, that number does change the CSI a bit so please include whatever your most recent salt level is.

As for CH, your fill water is going to raise it slowly. If you really want it higher in a shorter period of time you could add calcium to bring your water up to 300ppm, but it really isn't necessary. My annual increases in CH are measured in 100's of ppm and our fill waters are very similar.

Salt 3350

 

[JoyfulNoise]

Don't forget that water temp matters too, so make sure you input the correct water temp.


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[QingGuy]

It would be helpful to us if you could measure the pH, TA, and CH of your tap/fill water. That will help us predict your situation a little better, though the essence of it is as I described.

pH - 7.7
TA - 140 - 150
CH - 180-190