trichlor & salt?

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Self Evident

Self Evident

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Jul 28, 2016
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Polk County, FL
Ok, even in central Florida it's still winter (we've had some bone-chilling 60 degree overnight lows lateely!), which means I'm still staring at a pool cover, instead of my beautiful TFP. So, to pass the time until pool-open (a ways off - probably early March) I've been playing around with Pool Math, which has left me a little confused regarding trichlor & salt. Specifically, Pool Math indicates that tri-chlor adds salt, but I can't see/figure out how (a common malady I suffer whenever I try to think about something). Anyway, the reason this confuses me is because, after reading many many data sheets (like 3 or so), as far as I can tell, trichlor has no sodium (formula: C3Cl3N3O3).

So, would someone be kind enough to point out what I'm missing? It's been keeping me up at night & I need some sleep...

Thanks!
 
Even in pools that aren't salt water, all the other chemicals do contain a bit when broken down. If you test a regular pool's salt content after a few years you'd be surprised when it came back showing 1000 or so ppm of salt. Bleach and other products do contain trace amounts. We always suggest to folks who are switching from non-salt water to salt water pools to first test before adding their salt. If they didn't they may overshoot their desired salt level.

Maddie :flower:
 
Thank for quick respnse! I have often wondered what my salt level is, just out of curiosity. And I have considered a SWG, but the large start-up cost kills that option for me (at least for now). So I should have indicated that my original query is largely academic. Or, bored-ademic... :) I was trying to figure out the math of various chems, and was stumped when I noticed that Pool Math shows trichlor adding salt, if only a little. I just couldn't see where it's coming from (which is not an uncommon state for my mind...). In dichlor (aka "sodium dichloroisocyanurate dihydrate"), for instance, the sodium source is obvious. However, with trichlor, I don't see any refernece to sodium in the formula, or in any article or data sheet I've read. I'm hoping for a "duh!" moment so I can move on with my life, but for now I remain stuck on this quest for salinical knowledge...

ETA:
I should mention that what got me started was a bag of "pool shock" I have that is a granular trichlor. (I meant to get a couple bags of cal-hypo, and didn't bother to read the label...) It's data sheet says it is 53.5% trichlor by weight, with a couple of "Trade secret" components listed that make up 29% to 36% of the shock. So it's possible that some of those secret components, or even some of the 10.5% to 17.5% of unlisted ingedients, are salt. However, trichlor pucks/tablets are usually listed at 99 to 100% trichlor, and nothing else of substance...
 
Trichlor adds chlorine to the water and that chlorine eventually oxidizes something. When it oxidizes something, the chlorine is reduced to chloride ion (Cl-). The chloride ion is the "salt" that is referred to in Pool Math. There will always be a positive cation created during the process of chlorine oxidizing something and it matters very little if it's sodium or magnesium or calcium or some other positive ion. "Salt" tests like the K-1766 measure chloride ion (Cl-) concentration and the math of drops-per-ppm has in it the conversion to sodium chloride (NaCl) concentration. Making the assumption that the chloride is paired off with sodium is almost always a good assumption to make in normal water testing circumstances. An SWG cell doesn't care at all what the positive counter ion is as it is irrelevant to the electrochemistry of creating chlorine gas.
 
Ok. I think I understand. Or, at least it's starting to sink in. Which prompts a couple followup up queries/clarifications:

1) So, in general, a salt-water chlorine generator doesn't really care if the "salt" being electrolyzed is sodium chloride specifically? (Now that I've typed the question, the answer looks pretty obvious, but I don't want to assume...)

2)Regarding,
Making the assumption that the chloride is paired off with sodium is almost always a good assumption to make in normal water testing circumstances.
Click to expand...
Does that mean that there is usually some amount of sodium in the water that is not otherwise already part of a "salt"? In other words, is there some lonely little Na+ ion just floating around waiting for it's life mate, Cl-, to come floating by? In other other words: does Cl, after growing up in trichor, leaving home, and going thru a wild phase oxidizing whatever poor matter happened by first, finally realize that it needs to settle down with a good salt-mate?


In any case, thanks for the clarifications.
 
The SWG only cares about the chloride. All other ions are irrelevant. If you only had chloride ions in the water, the SWG would work just fine and wouldn't know or care that there were no other ions in the water.

Hayward Aquarite uses the performance of the cell to determine salinity. So, it would work ok.

Systems that use a conductivity meter (intellichlor, aquapure and autopilot) would read salinity as low if the other normal ions were missing. So they would shut down due to low salt reading even though they would work.

It does use water as a source of hydrogen. It reduces (gives an electron to) hydrogen to hydrogen gas and creates hydroxide in the process.

There are multiple ionic species in the water from various sources. Sodium is common and can come from sodium hypochlorite, sodium bicarbonate, sodium chloride etc.

Chloride can come from chlorine, sodium chloride, muriatic acid, calcium chloride etc.

Ions float in the water separately and so there really is no "salt" in the water.

When salt is added, the sodium ions and the chloride ions separate and go their separate ways. They wouldn't reconnect in any significant way until the concentration exceeded the solubility.

It would be almost impossible to have just chloride in the water. Even if you used chlorine gas for chlorination, you would have to use something basic to offset the acidity of the chlorine gas. You could use sodium hydroxide, sodium carbonate, sodium bicarbonate, sodium tetraborate etc, but, as you can see, they all contain sodium.

Trichlor is also acidic, so it requires a ph increaser as well.
 
Two key chemistry principles are these -

1. Mass balance (or conservation of mass); and
2. Charge neutrality

In any chemical equation, all sides of the equation must be balanced so as to conserve the number of atoms of each species present. This is call a mass balance. For example -

CaCl2 ----> Ca + 2 Cl

In plain English: 1 mole of calcium chloride dissociates into 1 mole of calcium ions and 2 moles of chloride ions.

Thus the weight of 1 mole of calcium chloride (110.98 grams) is equal to the weight of 1 mole of calcium (40.08 grams) plus 2 moles of chloride (2 x 35.45 grams).

Also, when dealing with ions in solution, charge neutrality must be met, ie, the sum of all positive and negative charges are equal. So, in our above example -

CaCl2 ----> Ca2+ + 2 Cl-

0 net charge ------> 2 (+) + 2 (-) = 0 net charge

With those two principles and a few fundamental numerical constants, most of chemistry can be figured out....
 
JamesW said:
Lithium carbonate is a salt. Just don't combine it with a portable power pack because that would be a salt and battery.
Click to expand...

I prefer lithium citrate as it has nice lemon-lime flavor and was once used in the formulation for 7-Up....

Lithium citrate - Wikipedia
 

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JamesW said:
There’s a hotel in Bolivia where everything is made of salt. Even the tables are made of salt. The salt that the tables are made of consists of sodium chloride, lithium chloride, and magnesium chloride. So, all three of those salts are table salts.
Click to expand...

I wonder if they have problems with large game animals wandering in to lick the tables :scratch:
 
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