Chlorine dioxide as an alternative to Ozone

FishOkay · May 6, 2022

forgive me if this sounds silly I'm no chemist. So we (my employer) install chlorine dioxide systems among other things for the water treatment industry. I got to talking with my boss and he was saying we have operations also in Thailand installing clo2 systems to the shrimp aquaculture industry and I couldn't believe it didn't just kill the shrimp until he said 0.01 - 0.04 mg/l then it made a bit more sense being so low. But it got me thinking could it be used in our aquariums as an alternative to ozone at these low doses? Looking a bit online it says there hasn't been any pr many studies on its effects on marine animals though so I'm not sure.
But If they are continually dosing it in the shrimp farming industry at such low doses to pretty much do the same as ozone, kill bacteria, pathogens and organic compounds and all that stuff and it's not killing the shrimp. Maybe it can? But I don't know it was just a thought haha

MnFish1 · May 6, 2022

There are at least a couple threads on this - and yes - its used to sterilize/purify water. There seem to be easier methods - with a wider 'therapeutic index' - i.e. the window where something has no effect - vs - kills everything.

taricha · May 6, 2022

Well, my first concern would be the way bleach (NaClO) makes nasty stuff from the bromine in seawater....
But it seems that's not expected to be an issue with ClO2.
"When NaClO was used as a disinfectant, total THM [trihalomethanes] account were 154±12 μg L−1 , whereas only up to 0.34± 0.03 μg L−1 were produced in the ClO2 treatment. The low production of THMs was also because ClO2 cannot oxidise bromide (Petrucci and Rosellini 2005). Therefore, at the ClO2 range tested, THM production could be virtually reduced by 100 %. Among the compounds, TBM [bromoform] was the most abundant, representing the 77–96 % of the total THMs in disinfected samples and reaching 148 μg L−1 when NaClO was used."
source attached.

So at least it's not as terrible an idea as bleach. So the more sensible comparison is Ozone. Not sure how it would be better than ozone or why an alternative to ozone is needed? It should be ORP-trackable like Ozone is.