Does Liquid Chlorine Raise TDS (Total Dissolved Solids)?

[00xavier]

I just returned from my pool supply store and they advised against using liquid chlorine. They told me liquid chlorine raises the TDS level to the point where your chlorine stops working because the water becomes too crowded. Is this true?

They recommended ProTeam Pure tabs that don't raise the CYA levels because they only contain pure trichlor. Is this true?

 

[Wildcat]

Run fast, run very very fast away from this store. Look at the MSDS

http://www.proteampoolcare.com/images/uploads/3_INCH_PURE_TABS.pdf

What is trichlor if not containing CYA?
What is their explanation on how CL raises the TDS? As far as your water knows CL is CL. Dichlor, trichlor and cal hypo contain other ingredients, bleach does not except water and sodium hypochlorite and a little sodium hydroxide.
Chem Geek is the expert here but I call BS on your pool store guys.
Read further on TDS and it turns out all solids and liquids we add to our pool increase TDS. I would post the article I found but I don't know if it is reliable as it was in a pool industry magazine

 

[chem geek]

How do they explain the effectiveness of chlorine in saltwater chlorine generator pools that typically have 3000 ppm salt in them (in the U.S.; in Australia it's 5000 ppm salt), let alone ocean salt pools with 35,000 ppm? What they are saying is total baloney. Also, Trichlor adds salt to the pool as well since ALL chlorine does that since the chlorine when used up becomes chloride (salt). However, while chlorinating liquid or bleach add twice as much sodium chloride salt as Trichlor, the Trichlor adds CYA which is far worse to build up than salt.

For every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.
For every 10 ppm FC added by Dichlor, it also increases CYA by 9 ppm.
For every 10 ppm FC added by Cal-Hypo, it also increases Calcium Hardness (CH) by at least 7 ppm.

The CYA from Trichlor is not added separately. Trichlor is a chemical that is a combination of chlorine attached to CYA. In the water, the chlorine is released from the Trichlor and the CYA remains ("trichloroisocyanuric acid" is three chlorine bound to cyanuric acid where you can see they are the same except that the chlorine "Cl" are replaced by hydrogen "H" which is what happens when the Trichlor gets into the water). The chlorine gets used up, but the CYA does not so it builds up. If you used "pure" Trichlor at a rate of 2 ppm FC per day, you'd increase the CYA level in the pool by 36 ppm per month.

Was this just some college kid who was temporarily hired during the summer to handle peak demand or was this a permanent employee or even the owner of the store? If the latter, you may remind them that fraud is illegal.

 

[timerguy]

Nobody's mentioned it yet, but you really need to get an adequate test it to do your testing yourself so you don't get pool stored or as i like to say-- les-lied. We recommend either the tf-100 or Taylor k-2006. Either can be ordered from tftestkits.net. Read all you can of pool school while you're waiting for it. Ask all the questions have, And everyone here will try to help you understand the TFPC way of taking care of your pool.

 

[easttn]

I see this kind of story quite often where the pool store has told someone something silly like that. Anything that is dissolved into water that is not water contributes to Total Disolved Solids. Every thing they sell will contribute to TDS. Distilled water would be the closest thing to 0 TDS and Ive never heard it called uncrowded water. Lol.

Im not a chemist but I have a good imagination and I image it would be something like this:
O=Water molecule.
T=Any type of Total Dissolved Solid.
X=Free Chlorine which needs to get to A (lets say algae spore) to sanitize it.
OTOOOT
X TOOTOA
OTOOOO

X has to flow around T and O to get to the algae spore.



Now lets say the same water with 0 TDS:
OOOOOO
X OOOOOA
OOOOOO

Now X has to go around more water molecules to get to A. See its just as crowded as it was before.

 

[easttn]

I was thinking about my illustration above and wanted to add that a TDS is probably going to be bigger than a water molecule since thats how reverse osmosis filters work but if one TDS took the space of four water molecules it would still take up the same space.

 

[chem geek]

I wouldn't bother to try and justify how someone could come up with this "crowded" water theory when clearly whoever came up with this had no real understanding of chemistry. First or all, the concentration of water compared to 3000 ppm salt (which is high and as I mentioned the amount typically used for salt water chlorine generators) is a factor of ((1000 g/L) / (18.01528 g/mole water)) / ((3 g/L) / (58.44 g/mole salt)) = 1081 so there are way, way, way, way more water molecules than salt. Now there is a small effect on chemical equilibrium from the charged ions (e.g. sodium and chloride) in the water from what is called ionic strength, but this effect is small and doesn't effect the uncharged molecule hypochlorous acid (i.e. chlorine that kills bacteria and algae).

Also, what causes water to become saturated with a dissolved chemical and to then precipitate that chemical as a solid has nothing to do with being "crowded". Some chemicals like table salt (sodium chloride) dissolve quite well into water while others such as calcium carbonate have more limited solubility and this has absolutely nothing to do with any sort of "crowded" theory. The differences are caused by differences in what is known as Gibbs Free Energy which is minimized at equilibrium but probably an easier way to understand it is that the bond strength between sodium and chloride ions is weaker than that of calcium and carbonate (in part due to sodium and chloride being singly charged while calcium and carbonate are doubly charged) so it takes a lot more sodium and chloride in the water so that they run into each other frequently enough to "stick" together compared to water hitting them and knocking them apart (also water stabilizes the ions because water is polar so has separated charge so acts in some sense like an ion in stabilizing other ions). Calcium and carbonate "stick" together more tightly so it takes less calcium and carbonate in the water before they stick to each other to form a solid. It's a statistical thing with the ions finding each other to stick together compared with water hitting them (and attracted to them) to force them apart.