Adding Cal-Hypo Causing Cloudiness

[ATXPool]

Hi,

On purchasing my last batch of Cal-hypo, I switched from pre-packed 1 lb. bags sold by In the Swim to a 25 lb. bucket of granules - Zappit 73. Every time that I add cal-hypo with the Zappit, my water turns translucent and milky for 1 to 2 days depending on if I run my filter 24x7. This never happened with the other brand.

What I'm wondering is there some type of anti-caking agent or something else causing the difference? They are both cal-hypo, but the Zappit at least has 27% "other" ingredients. I'm almost through this 25 lb. bucket and want to buy something next time that doesn't take my pool offline for a day or two.

Any suggestions for what to look for in cal-hypo?

P.S. I know bleach is better, but I've had trouble keeping up with the logistics of the quantities needed to keep the pool sparkling.

 

[Optica]

Do you have a quality test kit?
Can you post a complete set of test results, especially your PH, TA and CH.

Constant use of cal-hypo is raising your CH levels. I've seen many reports of cloudiness after adding cal-hypo.

 

[duraleigh]

P.S. I know bleach is better, but I've had trouble keeping up with the logistics of the quantities needed to keep the pool sparkling.

Well, your pool is not sparkling now so why do you feel cal-hypo is easier? it's not. Learn what you need to learn so you can use bleach and you won't have to worry about the cloudiness that is self-induced (and it sounds like you know it)

 

[ATXPool]

P.S. I know bleach is better, but I've had trouble keeping up with the logistics of the quantities needed to keep the pool sparkling.

Well, your pool is not sparkling now so why do you feel cal-hypo is easier? it's not. Learn what you need to learn so you can use bleach and you won't have to worry about the cloudiness that is self-induced (and it sounds like you know it)

It's sparkling except for the 1 or 2 days after adding this brand of cal-hypo. There is a logistical difference, but that not why I asked the question.

The cloudiness has shown itself across a range of PH from 7.0 to 8.0. This week is was 8.0. TA was high last time that I checked it, but so was PH, so not surprising. CH was 400 last time I checked (TH ~1500), which I realize it's high. Given no rain here in Texas and my only other source of water is 300 ppm well water, I haven't had the option to drain to dilute.

If I wasn't clear before, I'm asking about the differences between brands of cal-hypo, especially what other additives are in there - the "other" 27%. With the In the Swim brand, there was no cloudiness despite similar water conditions. The granules settled to the bottom generally with some parts floating on top. For Zapit, an instant cloud starts to progress from wherever the granules are added. That cloudiness persists for a day or two.

Any information about additives, or granule size, etc. that could explain the difference would be appreciated.

 

[JamesW]

The 73 % refers to the "Available Chlorine", not to the percentage of calcium hypochlorite. Although, it works out to about the same thing.

Anyway, the rest is sodium chloride, calcium chloride, calcium hydroxide, calcium carbonate, calcium chlorate, lanthanum carbonate and some water.

Zappit 73 is the same thing as Leslies Power Powder Plus, and is made by PPG. The Lanthanum carbonate seems to be unique to their calcium hypochlorite, but it is not more than 0.8 %, so I don't think that would cause too much trouble. Lanthanum carbonate is what is used in phosphate removers to precipitate out phosphate, but at only 0.8 % max, it should not have too much effect.

Either way, once your water gets anywhere near saturation with calcium carbonate, calcium hypochlorite will cause extended cloudiness. That's why I never use it.

http://www.lesliesmsds.com/DocumentCent ... 445a3e78df

http://www.aquapure-il.com/AutoIndex/un ... ZAPPIT.pdf

 

[ATXPool]

The 73 % refers to the "Available Chlorine", not to the percentage of calcium hypochlorite. Although, it works out to about the same thing.

Anyway, the rest is sodium chloride, calcium chloride, calcium hydroxide, calcium carbonate, calcium chlorate, lanthanum carbonate and some water.

Zappit 73 is the same thing as Leslies Power Powder Plus, and is made by PPG. The Lanthanum carbonate seems to be unique to their calcium hypochlorite, but it is not more than 0.8 %, so I don't think that would cause too much trouble. Lanthanum carbonate is what is used in phosphate removers to precipitate out phosphate, but at only 0.8 % max, it should not have too much effect.

Either way, once your water gets anywhere near saturation with calcium carbonate, calcium hypochlorite will cause extended cloudiness. That's why I never use it.

http://www.lesliesmsds.com/DocumentCent ... 445a3e78df

http://www.aquapure-il.com/AutoIndex/un ... ZAPPIT.pdf

Thanks for the feedback. I reviewed those MSDS, and that led me to double-check the In The Swim cal-hypo that I purchased. It turns out that the one that I used before was "pool shock" (65%) and not "super pool shock" (73%). The only listed difference that I could see was the Lanthanum carbonate.

A quick Google search which included references from this site, indicated that lanthanum carbonate can result in cloudy pool by precipitating out phosphates, as well as leaving extra carbonate ions around. I'm guessing those carbonates react with my hard water and contribute to the chalky film I've noticed lately. I know it's < 1%, but I'm not sure how much is a lot. I checked some phosphate remover MSDS and none that I found still use lanthanum carbonate. They use other lanthanum compounds, but generally in quantities in the 10% range. So, maybe ~1% is enough, especially when adding 3 lbs of cal-hypo.

Again I realize that I need to changeover my water, but need a lot of rain here in central Texas before that's a reasonable possibility. Really appreciate the help, James, and it looks like mystery solved. I'm going to try switching back to the 65% and will update this thread with the results.

 

[linen]

I'm going to try switching back to the 65% and will update this thread with the results.

Sounds like you already have a lot of calcium in your pool. Since you can't change out the water now, I think you need to stop using cal-hypo to not make you situation worse. What kind of pool do you have? in particular if it is a plaster/pebbltec then you need to keep your eye on the CSI value. You could post your latest ph, ta, ch test values (and fc, cc, cya while you at it).

 

[anonapersona]

It sounds like you are using the cal-hypo to do weekly shocks.

 

[JamesW]

Calcium hypochlorite is going to cause cloudiness, especially when your pH, TA and calcium hardness are high.

 

[dmanb2b]

At least cloudiness is cleared in a day or two....you next concern is scaling, which can be a pain in the behind, but it sounds like you are aware of the risks.