TriChlor shock powder - equivalent to pucks?

[polyvue]

Don't forget that for every 10 ppm Free Chlorine (FC) added by Trichlor, it also increases Cyanuric Acid (CYA) by 6 ppm.

Would this also apply to Leslie's powdered Tri-Chlor Genesis Shock?
The specs are
10 oz bag
Trichchloro-s-triazinetrione 67%
aka Trichloro Isocyanuric Acid
Available chlorine 60.3%

I read somewhere that this product has a "neglible" affect on CYA. Not sure what that means, however.

When applied to my 14K gallon pool, 1 bag seems to increase chlorine by about 4 ppm. I have not sought to measure the CYA difference.

[chem geek]

This has exactly the same effect on CYA as Trichlor pucks. For every 10 ppm FC it will increase CYA by 6 ppm. It is less concentrated by weight than solid pucks, but that just means you'll use more and the rule of 10 FC with 6 ppm CYA is independent of concentration of product or of pool size. Whatever amount of this Trichlor powder that you add to get to 10 ppm FC, it will add 6 ppm CYA. Period.

[polyvue]

Whatever amount of this Trichlor powder that you add to get to 10 ppm FC, it will add 6 ppm CYA. Period.

This clarifies the situation for me.

So the fact that

that [Genesis TriChlor shock] has a "neglible" affect on CYA

and "is guaranteed not to raise calcium levels" is really misleading and superfluous, respectively.

CYA is increased by its application in a ratio of chlorine/cyanuric acid 10:6 ppm and calcium/potassium chloride is notably absent and therefore, not increased.

I think I have it!

[duraleigh]

As a slightly off-topic comment, I only found out recently that tri-chlor powder exists.

It would seem to me not to be a very useful product as Cal Hypo would better to shock a pool by being quicker to get Cl into the water. (Liquid chlorine or bleach still being, by far, the best for shocking).

[polyvue]

It would seem to me not to be a very useful product as Cal Hypo would better to shock a pool by being quicker to get Cl into the water.

I don't have any figures or test results to back this up, but I think powdered trichlor is very quick to add chlorine to the water. Once a bag is tossed in the water (I mean, of course, the contents!) it instantly dissolves; a small portion remains floating on the surface -- I've always assumed this to be the cyanuric acid portion -- for about 5 minutes. But in my little pool, I can detect (via FAS-DPD test) the highest level of chlorine in about 15 minutes.

I've nothing against Cal Hypo, of course, but the calicium level is stagnate in my pool, while I'm always having to add CYA due to the "Three Outs": Splash-, carry- and spit- (the last actually emanates from my Polaris 280's fuzzy tail.)

[duraleigh]

Poly,

That's an interesting answer and then would certainly make it a product with a purpose. I assumed it dissolved very slowly. I learn something everyday.

[JasonLion]

Powdered trichlor dissolves much more slowly than either cal-hypo or dichlor. In many cases it dissolves quickly enough, but it does not dissolve instantly.

[polyvue]

Powdered trichlor dissolves much more slowly than either cal-hypo or dichlor. In many cases it dissolves quickly enough, but it does not dissolve instantly.

Well, as I said in my second post, I have no figures to back up my assumption, other than it appears to dissolve instantly and maximum chlorine can be measured in my smallish pool (~80 GPM w/cleaner and water features turned on) in about 15 minutes from the time of application. There are anomalous large particles that float on the top for 5 - 10 minutes -- I've always figured this was the CYA content, but for all I know it could be floor sweepings!

To be clear, I'm not promulgating the use of Trichlor shock via this forum. Perhaps it has worked for me for the reasons I've stated (constant need to add CYA, no visible algae, no or very low detected combined chlorine cc, very occasional application.)

[chem geek]

Since Dichlor dissolves more readily and adds even more CYA than Trichlor, one can use Dichlor when one wants to add both chlorine and CYA at the same time. If you use Trichlor, then the pH can drop a lot more since Trichlor is quite acidic. Even with Dichlor the pH can drop as the chlorine gets used up, but with Trichlor it drops even more. If one wants to 1) add chlorine, 2) increase CYA and 3) lower the pH, then Trichlor would be the way to go.

[polyvue]

If one wants to 1) add chlorine, 2) increase CYA and 3) lower the pH, then Trichlor would be the way to go.

Richard,

You've provided the answer as to why this product seems to work for me, since 1, 2 & 3 are goals in keeping with my usage (every few months) of Trichlor. In my stupid fashion, I stumbled upon this product and though I don't know if it's been truly effectual at shocking (evidenced by my Labor Day fiasco, where I attempted to shock 0.2 ppm cc from the pool water; needlessly, I now understand) it probably hasn't done any harm either.

I thank you for your contribution to my evolving understanding!

Greg

BTW - I started using trichlor to obviate last-minute trips to the pool store for 10% sodium hypochlorite, whose strength when stored dissipated very quickly over the summer in my 100 degree uninsulated garage. Perhaps I'd be better off just buying 6%, storing it inside.

[gstein]

... If you use Trichlor, then the pH can drop a lot more since Trichlor is quite acidic. Even with Dichlor the pH can drop as the chlorine gets used up, but with Trichlor it drops even more. If one wants to 1) add chlorine, 2) increase CYA and 3) lower the pH, then Trichlor would be the way to go.

And this is exactly why I just tossed some bags of trichlor shock into my pool. My pH is over 8.0(!!!), my CYA is 30 (but I target 60+ for handling the Texas sun), and well... it's green, coming out of the winter months. Mucho chlorine needed! I threw in a cup of muriatic acid just to help get that pH into measurable levels by tomorrow.

I've got CYA standing by for after my SLAM is done. And I've got 10 gallons of 10% bleach for when my pH stabilizes.

(the pool calculator's "Effects of adding chemicals" says 48 oz of trichlor should get my pH into proper range... will test in 4-5 hours)