Best operating temp for chemicals to work

[Timberwolf]

What is the best temp for the pool chemicals to work? Or does temp even matter as long as the ph is correct. I'm being told that the pool heat "has to be" over 86 degrees for the chemical to function. We have both liquid and tabs cholrine. It an outdoor in ground pool. We have a gas heater and solar cover. The heating bill and chemicals are very high. I don't believe that the temp has to be that high but that the ones stating just want the pool heat up. Thanks

[Guest]

chlorine works better at lower temperatures and loses activity and becomes more volatile as the temperature increases.

low temperatures are therefore better than high ones for chlorine efficiency.

[chem geek]

This is not true. ALL chemical reactions speed up at higher temperatures and this includes chlorine killing of pathogens. The reproduction rate (generation rate or rate of doubling in population) of pathogens increases more slowly with temperature than most chemical reactions -- because there are physical processes that occur with reproduction as well. The CT (chlorine in ppm times time in minutes) values for pathogens gets lower as the temperature goes up, meaning that it takes lower chlorine concentrations to kill pathogens as quickly (or conversely that the same chlorine concentration kills pathogens more quickly).

It is true that the volatility (outgassing) of chlorine increases at higher temperature, but with Cyanuric Acid (CYA) in the water the active chlorine level is low so this effect is negligible until you get to hot tub temperatures. Most of the chlorine loss in residential pools is due to breakdown from the UV in sunlight (in commercial/public pools, most of the chlorine consumption is from oxidizing the urea, ammonia and other chemicals in sweat and urine plus swimsuits, skin, hair, etc.).

It is not true that the pool needs to be 86F or higher for the chemicals to work properly. That's just baloney.