I am not quite sure what the logic is here. Of course you can achieve complete sterilization with chlorine bleach. It is no problem to achieve 50-100 ppm or even more with sodium hypochlorite. See this document from CDC that describes how much you need to sterilize various things
https://www.cdc.gov/hicpac/Disinfection_Sterilization/6_0disinfection.html
There is no reason to wait a long time for the chlorine to evaporate. Get some sodium thiosulfate and use it directly to neutralize the chlorine once the time you want to treat has elapsed. See here
http://www.edspumps.com/water-treatment/documents/Antichlorination.pdf
for a chart that tells you how much thiosulfate you need to neutralized chlorine. An easy test is to simply smell it. When you can't smell chlorine any longer, it is gone.
One issue with using chlorine is that it can react with organic material to generate halogenated hydrocarbons which can be toxic/carcinogenic. I'd expect that carbon after the sodium thiosulfate neutralization will get rid of any of those still around.
Or am I missing something important here?
Bruce
https://www.cdc.gov/hicpac/Disinfection_Sterilization/6_0disinfection.html
There is no reason to wait a long time for the chlorine to evaporate. Get some sodium thiosulfate and use it directly to neutralize the chlorine once the time you want to treat has elapsed. See here
http://www.edspumps.com/water-treatment/documents/Antichlorination.pdf
for a chart that tells you how much thiosulfate you need to neutralized chlorine. An easy test is to simply smell it. When you can't smell chlorine any longer, it is gone.
One issue with using chlorine is that it can react with organic material to generate halogenated hydrocarbons which can be toxic/carcinogenic. I'd expect that carbon after the sodium thiosulfate neutralization will get rid of any of those still around.
Or am I missing something important here?
Bruce
I wanted to document this entire process, explain how to do it and what to expect to achieve from doing it. Reading this thread will provide some background info.
First off, you cannot expect to achieve complete sterilization from dosing chlorine into a QT. Eradicating Ich (Cryptocaryon) tomonts, for example, requires maintaining 60 mg/L chlorine for 24 hours (source here - Table 2); but that seems difficult to achieve.Also, I think using that much chlorine could damage equipment/pumps used in a QT.
So the concentration I am shooting for with this experiment is 10ppm (or mg/L). According to this source that should be good enough to reduce most bacteria, protozoa and virus populations by 99.99%.
With this in mind, I've setup a 10 gal QT with all the usual equipment (photo below - removed some water to avoid bleach splashing out of the tank). This morning @ 9am I dosed 1/4 cup of regular liquid bleach (8.25% sodium hypochlorite) to achieve 10ppm chlorine. (Actually, just slightly higher than 10ppm.) This turned the QT cloudy and slightly yellow.
Monday @ 9am: >10ppm chlorine
Monday @ 3pm: >10ppm chlorine (+6 hrs)
Tuesday @ 12am: >10ppm chlorine (+15 hrs)
Tuesday @ 10am: >10ppm chlorine (+25 hrs)
Wednesday @ 10am: >10ppm chlorine (+49 hrs)
