Trichlor Question

[Tubblin]

Is Trichlor the same as Trichloro-s-triazinetrione tablets. The reason I'm asking is that my cya doesn't rise with these tabs like it is supposed to with Trichlor. I bought a Taylor K-2006 this year and the black dot dosen't disapear. I use these tabs in my pool and want to switch my spa from bromine tabs to these tabs so I don't have to buy both kinds of tabs.I put the recommened amount of cya in the pool(per the pool calculator) to get it up to 30ppm. I will wait a week and retest. In my pool I keep the chlorine between 2-4 with the tabs and shock with bleach at least once a week depending on load. Will that be ok for the spa? If so, should I do the first shock with bleach or crushed up tabs.

Thanks for reading

[chem geek]

Yes that's Trichlor and for every 10 ppm Free Chlorine (FC) it also increases Cyanuric Acid (CYA) by 6 ppm, so not as fast as with Dichlor which adds 9 ppm CYA for every 10 ppm FC. If you aren't seeing the CYA rise then either you don't have a proper test kit (the Taylor K-2006, for example) or you have enough water dilution and too short a season to notice the rise. The weekly shocking with bleach probably has you use a lower amount of chlorine daily from the Trichlor so the buildup is slower. At 1 ppm FC per day from Trichlor, the CYA would rise by 18 ppm if there were no water dilution.

Trichlor generally dissolves too quickly in hot spa water and its very acidic which is riskier in a smaller volume of water in a spa so generally we do not recommend using Trichlor in a spa. If you want slow dissolving tablets for a spa, then you should use bromine. If you want to use chlorine, then the Dichlor-then-bleach method would work, but you have to dose every day or two so is usually best for those who use the spa frequently.

[Tubblin]

Thanks for the advice Chem geek. I think I'll go back to bromine. I was just hoping I could use the same sanitizer and tester (Taylor K-2006) in both the pool and spa. Can I use the R-0872-A reagent in my K-2006 tester to test for bromine? If so, what would be the procedure?

Thanks for reading

[arches2]

your R-0872 is used for bromine. You should have R-0871 in the k-2006. you can use either in a BR spa, just use a different multiplier for the drops. In BR R-0872 is 1.25 drops per PPM in 10ml (0.5 ppm / drop in 25ml) and the R-0871 should be onthe lid of the k-2006 for cl. What ever that is (don't know off the top of my head) multiply the result by 2.25 to get total br.

[Tubblin]

Thanks for the advice arches2. I have printed out your response and will put it my tester box.

[cookster]

Hi

I have a 450 gallon tub and have been using the Dichlor bleach method more recently, my question is if I am going away for 5-6 days can I switch to Trichlor Tabs in a floater without experiencing too much of a PH drop, would increasing PH prior to travel be a possible mitigation of lowering PH over this period of time. My current stats are:

1. PH 7.5
   
2. TA 130
   
3. CH 170
   
4. CYA 80 (Got high before I read about bleach combination)
   
5. FC 4
   

I use a test kit to get these numbers but not a Taylor as I cannot seem to find a supplier in the UK

[chem geek]

No, unfortunately you can't switch to Trichlor in a hot tub because it dissolves too quickly in the hot water. There is a product that uses Trichlor tabs in a special feeder for slow dissolution (Aqua Finesse®), but as they note at the bottom of the page, they aren't compatible with all spas (probably void the warranty, depending on spa manufacturer).

If you don't have an ozonator and typically have only a 25% daily loss in Free Chlorine (FC) level, then you could just shock the spa up to 15 or 20 ppm which should result in an FC of around 2.7 to 3.5 when you return. If you lower the spa water temperature (say, to 80ºF), the chlorine will last longer. 20 ppm FC with 80 ppm CYA is still a low active chlorine level, especially at the lower temperature. If you have an ozonator, however, the chlorine demand may be high and lowering the temperature won't help with that part of the loss.

[cookster]

HI

Thanks for the reply,

other than the quick dissolving, is the warranty problem because of acidity? can this be mitigated by raising PH or are there other problems. I guess my alternate course of action would be to switch to bromine tabs and then drop the water if I wish to return to chlorine.

There is a company in the uk "Aquasparkle" http://www.splashspas.co.uk/aquasparkle/aquasparkle-spa-multifunctional-chlorine-tablets-500g.htm that sell trichlor for spas but I guess trichlor is..... Trichlor!!

[chem geek]

Yes, the warranty problem is primarily due to the acidity and having the FC get too high. The combo is not good for spa components (especially the acidity). Yes, you can help mitigate the acidity by having the TA (pH buffering) be higher and starting with a higher pH, but it's hard to predict the Trichlor dissolving rate and how fast carbon dioxide may outgas (though keeping the hot tub covered should lessen that). However, a hot tub warranty doesn't care what you do -- if they say not to do something and the manufacturer has any evidence of it, your warranty is void.

[arches2]

The best advise chem geek gave here that was kind of glossed over is, Turn the temp down to 80. That will not only save you $$$ it will lower the demand of sanitzer.

[cookster]

Hi

thanks I will definetly do that