Cal Sok Calcium Reducer

Buggsw

LifeTime Supporter
Apr 22, 2007
925
Arizona
#1
I was in Leslie's today and saw a product called Cal Sok.

Inside the bottle is a bag of "stuff" that you put in your skimmer for 24 hours that is supposed to absorb calcium into whatever that "stuff" is.

It's supposed to reduce calcium by 200 in 10-15K pool within 24 hours.

I can't find anything out about what the ingredients are. I did find the manufacturer.
http://www.coatingsystemslaboratories.com/calsok.htm

So, I was wondering if anyone here had ever used it or knows any more about it, like what the ingredients really are.
Editing to say I found a document at leslies msds site that says it is an organic polymer family.
http://www.lesliesmsds.com/Document/1/5 ... b88f7c.pdf

So what does that mean to a pool? What is it really doing?

Edited again to say I found several sources that say they use organic polymers in city water treatment. That the organic polymers can be flocculent, coagulent or agglomerent. I'm thinking by the description of the instructions I read while at Leslie's that this particular one must be agglomerent.

Now, I'm thinking that the Calsaway company that brings a truck in to pump and filter your water must be using something like this. Seems to me there was a video of a treatment they poured some stuff in the water that either flocced or coagulated the calcium.

At Wikipedia I found a statement I'm not sure how to take. It says "The drawbacks of polymers are that they are expensive, can blind sand filters and that they often have a very narrow range of effective doses."
http://en.wikipedia.org/wiki/Water_purification

What does "can blind sand filters" mean?


Am I close on any of this?
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#2
I don't see how their claims could be true. 200 ppm in 15 K gal would be 27 lbs of calcium chloride. I don't see how that could fit in the skimmer, even if it could magically get it to "stick" to the "sok". If it fits in a skimmer it can't possibly take out 200 ppm in a single go. Perhaps you need to take it out and "recharge" it every hour? Also, their web site is rather broken, not at all an encouraging sign.
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
#4
200 ppm Calcium Hardness (which is measured as ppm Calcium Carbonate, not Calcium Chloride) is equivalent to 80 ppm of Calcium alone, so that would be 8.33 pounds/gallon * 80 * 10,000 / 1,000,000 = 6.7 pounds of calcium. It is not clear if you need to use multiple 1-pound bags of Cal Sok but if there was a 1:1 molar attachment, then that would mean the Cal Sok substance had a molecular weight of around 6 so I suspect that they are using Fluoride since Calcium Fluoride is virtually insoluble in water. Fluoride has a molecular weight of about 19 and it takes two fluoride per calcium so that to precipitate 6.7 pounds of Calcium it would take 6.7 * 2* 19 / 40 = 6.4 pounds of fluoride. Of course the fluoride has to be a molecule as a solid, not an ion, so Sodium fluoride would make sense and has a molecular weight of 42 so that's 6.7 * 2 * 42 / 40 = 14 pounds of Sodium fluoride.

Magnesium fluoride is slightly soluble in water at about 76 ppm so is consistent with their claim of reducing multiple scaling species.

Anyway, this is just speculation on my part.

Richard
 

Buggsw

LifeTime Supporter
Apr 22, 2007
925
Arizona
#5
The jar was gosh, maybe 1 or 2 lbs at most. Maybe the size of a one lb coffee can, the ingredient is in a bag inside the jar.
The instructions were to lower your chlorine to under 3ppm and place this bag in the skimmer and run your pump for 24 to 48 hours, then remove the bag and it was only supposed to consist of 1 treatment which would reduce the calcium by 200 ppm.

Dang, I hate it when they don't list ingredients.
 

JasonLion

TFP Expert
Platinum Supporter
LifeTime Supporter
May 7, 2007
37,879
Silver Spring, MD
#6
Hum, their site had numerous broken links when I first tried it, but it is just fine now.

They say it is a 1 lb bag. I don't see where they are going to stuff the 6.7 pounds of calcium and have the skimmer continue to work. What if it disolves in the skimmer, or gets carried into the filter as a powder, and binds to the calcium in a way that somehow that ends up getting filtered out? What could bind to nearly seven times it's weight in calcium?
 

chem geek

TFP Expert
LifeTime Supporter
Mar 28, 2007
12,082
San Rafael, CA USA
#8
This link seems to indicate that the anionic (positively charged) polymer known as poly(acrylamide-co-vinyl phosphonate) (abbreviated PAMVP) "bound soluble calcium ions, resulting in the formation of multichain colloidal-sized clusters". This is consistent with the Cal-Sok saying that it is a proprietary organic polymer. Note that it is insoluble in water and you pour it into the skimmer so that it gets caught in the filter. Presumably it captures calcium more selectively than sodium (the polymer probably is made neutral using sodium so in effect it is somewhat like an ion exchange resin substituting calcium with sodium when put into use). After treatment, you would need to clean or backwash the filter to remove the solid "calcium bound to organic polymer" material.

I still find it quite amazing that this polymer can presumably lower CH by 200 ppm via one pound added in 10,000-15,000 gallons (see this link). 200 ppm of CH is about 2 millimoles per liter or in 10,000 gallons this is 75.64 moles which is 3030 grams or 6.7 pounds. So the polymer is able to capture nearly 7 times its weight in calcium.

I don't know if that is also what Calsaway is using. Calsaway could be just doing the following:

1) 2 pounds Sodium Carbonate (Soda Ash; Washing Soda; pH Up) per 10,000 gallons
which raises pH from 7.5 to 8.42 (if the TA started at 100) and raises saturation index by +0.9

2) Filter out calcium carbonate, using a flocculant if necessary, or a fine filter or membrane.
which can lower the Calcium Hardness by 23 ppm to get the pH and saturation index back to where it started.

Repeat the above, possibly using more extreme conditions (i.e. can add Lye / Caustic Soda / Sodium Hydroxide in step 1 and Muriatic Acid after step 2). The above essentially substitutes sodium for the removed calcium. If this is done in a specialized vessel, then the scaling won't affect the pool itself.

It would take about 10 pounds of Sodium Carbonate per 10,000 gallons to reduce the CH by around 100 ppm.

Richard