Water Conditioner, Is It Worth It

[mike os]

quotes or paraphrased as I cant cut from the article....

.... tanks treated with sodium thiosulphate......

....0.2 after treatment....does not give initial dose therefore could be anything.... but states "... variable levels..."


.....investigated in 96h to 20 day lab exposure..... one assumes exposure means "kept at xx ppm for....."


real data = treated xx fish at y size in xx conditions with xx ppm for aa time..... results.... analyses....conclusion.

not the above.... what ?, kept for 96h at 500ppm? 20 days at 0.0000001ppm? report this is not "real data", more a typical "press release"

 

[rhostog]

quotes or paraphrased as I cant cut from the article....

.... tanks treated with sodium thiosulphate......

....0.2 after treatment....does not give initial dose therefore could be anything.... but states "... variable levels..."


.....investigated in 96h to 20 day lab exposure..... one assumes exposure means "kept at xx ppm for....."


real data = treated xx fish at y size in xx conditions with xx ppm for aa time..... results.... analyses....conclusion.

not the above.... what ?, kept for 96h at 500ppm? 20 days at 0.0000001ppm? report this is not "real data", more a typical "press release"

I think perhaps you might be misinterpreting this document. The paper does not describe a study to test the toxicity of chlorine (which would of course require a differently structured controlled study of the sort you describe - I've not found one available on the internet yet but would be very interested to read one); it is an examination by veterinary pathologists of the effects of chlorine at a cellular level. While it doesn't directly answer our questions about the need for chlorine neutralisers, it is informative in as far as it discusses the effects of chlorinated water on one particularly sensitive species - no more than that.

I wonder if you may be misunderstanding the 'case history' section - I understand it to be saying that the fish keepers had treated the water with sodium thiosulphate, but didn't use enough, so there was still 0.2ppm chlorine in the water. The reason they mention the 'variable levels' of chlorine is to explain why the fish keepers had failed to use enough sodium thiosulphate - the water they were getting was unusually high in chlorine over that period. Not sure what you mean by 'initial dose'? The fish were exposed to 0.2ppm chlorine - I don't see it matters in this context exactly how much chlorine had been effectively neutralised, just that the net amount of chlorine remaining afterwards was 0.2ppm.

The fish were kept in water containing 0.2ppm chlorine for 10 days. It wasn't in a lab under controlled conditions because that wasn't the purpose of the study, but it does state clearly what the conditions were. As mentioned before, this isn't a paper describing an experiment to see how much chlorine it takes to poison a fish - it's a study of the effects of chlorine on the cells of one species after this one incident.

The reference to 96h - 20 days is a summary of the results in another paper (Svecevicius), not the authors' own findings. You would need to read the original to find out the details of this study, but it seemed to be about the relative toxicity of chlorine dioxide and chlorite, which is a different discussion I think.

I'm not sure why you're suggesting this is in the nature of a press release (on whose behalf?!!) It's a technical scientific paper published in an academic journal. The main authors are veterinary pathologists, examining the effects of chlorine at a cell level. Press releases written in this sort of language wouldn't get very far!

Edited for typos - should be 0.2ppm instead of 2ppm

 

[Bignose]

Those numbers of 0.02 and 0,04 ppm seem rediculously low to me.

Look at this quote from "Survival of cool and warm freshwater fish following chloramine-T exposure" by Gaikowski, Lawrson, and Gingerich, Aquaculture, 2008:

Abstract: Chloramine-T is presently available in the USA to control mortalities associated with bacterial gill disease or external columnaris only through an Investigational New Animal Drug Permit authorized by the US Food and Drug Administration (FDA). Its US approval hinges on FDA's acceptance of several key data, including those describing animal safety. Chloramine-T is presently applied in US aquaculture, by permit only, once daily on consecutive or alternate days for 1h at 10 to 20 mg/L to control mortalities associated with bacterial gill disease or external columnaris. Our objective was to determine the safety of chloramine-T bath exposures at multiples of the proposed maximum treatment concentration (i.e., 0, 20, 60, 100, and 200 mg/L) administered on four consecutive days at 20 degrees C to lake sturgeon Acipenser fulvescens, northern pike Esox lucius, and walleye Sander vitreum, or at 27 degrees C to channel catfish Ictalurus punctatus, and largemouth bass Micropterus salmoides. All fish were tested as five to eight week old fry except for walleye and channel catfish which were tested as both fry and fingerling (fingerlings were at least four weeks older than the fry tested). Walleye and channel catfish were selected to evaluate the effects of life stage (fry vs. fingerling), temperature (walleye - 15, 20, or 25 degrees C; channel catfish - 22, 27, or 32 degrees C), exposure duration (60 vs. 180 min), and water chemistry (walleye only - reconstituted soft water vs. well water). Except for channel catfish fry, survival was significantly reduced only when fish were treated at 100 or 200 mg/L. Channel catfish fry survival was significantly reduced when exposed at 60 mg/L for 180 min at 27 degrees C. Based on our mortality data, chloramine-T administered once daily for 60 min on four consecutive days at concentrations of up to 20 mg/L is not likely to adversely affect survival of cool or warmwater fish cultured in freshwater (emphasis mine)

In particular, look at that sentence that I bolded -- concentrations of up to 20 ppm! 1000-fold higher than the numbers you cited! Now, sure, I am going to be the first to agree that "survive" is nowhere near the same as "thrive" and thriving is the goal of every good fishkeeper. But, I don't see how there could be a thousand-fold difference in the numbers.

 

[rhostog]

Those numbers of 0.02 and 0,04 ppm seem rediculously low to me.

Look at this quote from "Survival of cool and warm freshwater fish following chloramine-T exposure" by Gaikowski, Lawrson, and Gingerich, Aquaculture, 2008:

Abstract: Chloramine-T is presently available in the USA to control mortalities associated with bacterial gill disease or external columnaris only through an Investigational New Animal Drug Permit authorized by the US Food and Drug Administration (FDA). Its US approval hinges on FDA's acceptance of several key data, including those describing animal safety. Chloramine-T is presently applied in US aquaculture, by permit only, once daily on consecutive or alternate days for 1h at 10 to 20 mg/L to control mortalities associated with bacterial gill disease or external columnaris. Our objective was to determine the safety of chloramine-T bath exposures at multiples of the proposed maximum treatment concentration (i.e., 0, 20, 60, 100, and 200 mg/L) administered on four consecutive days at 20 degrees C to lake sturgeon Acipenser fulvescens, northern pike Esox lucius, and walleye Sander vitreum, or at 27 degrees C to channel catfish Ictalurus punctatus, and largemouth bass Micropterus salmoides. All fish were tested as five to eight week old fry except for walleye and channel catfish which were tested as both fry and fingerling (fingerlings were at least four weeks older than the fry tested). Walleye and channel catfish were selected to evaluate the effects of life stage (fry vs. fingerling), temperature (walleye - 15, 20, or 25 degrees C; channel catfish - 22, 27, or 32 degrees C), exposure duration (60 vs. 180 min), and water chemistry (walleye only - reconstituted soft water vs. well water). Except for channel catfish fry, survival was significantly reduced only when fish were treated at 100 or 200 mg/L. Channel catfish fry survival was significantly reduced when exposed at 60 mg/L for 180 min at 27 degrees C. Based on our mortality data, chloramine-T administered once daily for 60 min on four consecutive days at concentrations of up to 20 mg/L is not likely to adversely affect survival of cool or warmwater fish cultured in freshwater (emphasis mine)

In particular, look at that sentence that I bolded -- concentrations of up to 20 ppm! 1000-fold higher than the numbers you cited! Now, sure, I am going to be the first to agree that "survive" is nowhere near the same as "thrive" and thriving is the goal of every good fishkeeper. But, I don't see how there could be a thousand-fold difference in the numbers.

That's an interesting reference - I was surprised that these fish were so tolerant of chloramine. The following page also makes interesting reading (although some of the links are broken) and supports your reference above, that chloramine is far from the 'deadly' chemical implied by water conditioner manufacturers.

[URL="http/www.skepticalaquarist.com/docs/water/chlorine.shtml"]http/www.skepticalaquarist.com/docs/water/chlorine.shtml[/URL]

I also found this table showing toxicity data references from the 'Pesticide Action Network' (an organisation campaigning against pesticides, so may be likely to record worst cases). Note that concentrations are given in micrograms rather than mg - some of the data is for mortality, some for behavioural changes, some for young fish etc. so it's not very consistent - but it does at least point to original source data. If you skip down to the mortality section for adult fish, the table seems to show mortality at chlorine levels between hundreds of micrograms/L to 1 or 2 mg/L, whereas the equivalent table for chloramine shows typical mortality at tens or hundreds of mg/L - consistent with the figures you cited.

[URL="http/www.pesticideinfo.org/List_AquireAll.jsp?Rec_Id=PC33637&Taxa_Group=Fish"]http/www.pesticideinfo.org/List_AquireAl...Taxa_Group=Fish[/URL]

The total chlorine concentrations in the rainbow trout paper were 0.2ppm (just corrected my typo in the earlier post - sorry, must stop reading these forums and working at the same time), but your point still stands that is very different (100-fold) from 20ppm. This could be explained by the fact that it was chlorine in the form of chlorine dioxide and Cl2, rather than chloramine.

Given the variability in sensitivity of different species, varying concentrations of chlorine found in local water, variable toxicity at different pH, chlorine as Cl2 versus chloramine - I guess it's not surprising that many people successfully keep fish in untreated water. Very interesting too that chloramine doesn't seem to be particularly harmful in typical tapwater concentrations, so gassing off chlorine may be effective even for chloraminated water.