Thread: Sodium Thiosulfate + EDTA Tetrasodium Salt and V's Tap Water Dechlorinator?

I'm looking to make up my own dechlorinator mix to add to my pond as i'm finding even with 3 big blues that it doesn't take long for traces of chlorine/byproducts to start creeping through.
even though all the free chlorine is getting mopped up...
and i noticed an improvement in my fishes activity and behaviour when i have dosed a small amount of ST now and then.


There aren't many people who keep koi that don't know about ST (Sodium Thiosulfate)

but most proprietry dechlorinators also include a heavy metal chelating agent like EDTA Tetrasodium Salt,

but i can't find much information on dosage rates for EDTA other than a stock solution of 5g (1 tsp) dry powder EDTA to 113ml (4 floz water) and then 0.05ml (2 drops) per 3.78 litres (1 U.S. gallon) of tap water.

the other thing with EDTA is it can lower ph so too high a dosage could be very bad.



i wouldn't even need a full dose as most of the chlorine and nasty pesticides ect... are removed by the big blues,
but i'm getting fed up of restratifying the carbon every few weeks to keep chlorine at 0ppb due to my nasty poisonous high chlorine and trihalomethane mains tap water.
and want to mop up any small amounts that get past with a dechlorinator.

is it just considered easier to buy a branded dechlorinator rather than use EDTA or just not worth bothering with?

EDIT: but not kusuri dechlorinator as it's just 13% sodium thiosulfate and 87% water and less than 0.1 blue dye%...
@£69 for 5 litres

Completely lost !! Where the main man manky !!

Reminds me I really need to sit down and have a look at his courses .

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Originally Posted by Ajm

Completely lost !! Where the main man manky !!

Reminds me I really need to sit down and have a look at his courses .

Sent from my SM-G973F using Tapatalk

i'm about to start using my dosing pump with bicarb, as i'm at 2KH @ 7.2 pH now and don't want it to go any lower.

i can get a dechlorination liquid that will do 6 months worth at 91,000 litres for about £40.
but i know it's mainly sodium thiosulfate and EDTA, with a bit of aloevera thrown in...

when the raw ingredients will do over half a million litres
maybe i'm just tight but i'd rather know exactly what im dosing rather than a mysterious 'mix of ingredients'....

2kg of ST @ £18 will do 666,000 litres or much more if it's already partially or mostly dechlorinated...
1 kg of EDTA @ £18 will do 800,000 litres

maybe it's too dangerous an ingredient in a raw state thats why you don't see too much of it....
API's dechlorinator MSDS sheet.

https://www.apifishcare.com/pdfs/pro...data-sheet.pdf

Wow
. Nowt to do with tight mate have to make savings where we can

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Originally Posted by Ajm

Wow
. Nowt to do with tight mate have to make savings where we can

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i'm not about to start doing my own experiments to find a safe level to dose EDTA at, as i can't find conclusive infomation about dosage rates on the web anywhere.
it's a shame as it would be good information for the hobby in general...
...assuming that EDTA isn't wildy carcinogenic or dangerous in it's raw powdered state...

so it's looking like i'll have to buy a dechlorinator pre mix,
and probably use at half dose as the water is carbon filtered and most of the bad stuff has been taken out....

anyone got any favorite dechlorinator pre mixes?
API, kusuri, aqua balance vitalise?

I normally rely on my big blue and on occasions ST. The only actual off the shelf product I've used in recent years, was the Colombo fish protect.

Originally Posted by g mac

I normally rely on my big blue and on occasions ST. The only actual off the shelf product I've used in recent years, was the Colombo fish protect.

the crazy thing is i used to manage fine with two 10" 3 pod filters,
a sediment and two GAC in the first 3 pod, and a spectrum standard 5 micron carbon block, and two 1 micron chloramine premier carbon blocks.
but that was when my tapwater had 0.1ppm - 0.2ppm of chlorine in it and not much else...

not the 0.6ppm - 0.8ppm of chlorine and load of chlorine byproducts it is now...

i used the colombo fish protect last year, after a long list of treatments for flukes to help de toxify all the chemicals from the water.
but is not particularly cheap to use as a dechlorinator.

2.5litres of colombo fish protect at £30 will dechlorinate 50,000 litres
where as 5 litres of kusuri dechlorinator at £49 will do 225,000 litres

at 400 - 500 litres a day for the drum and recycle RO waste replacement. my annual use would be around 182,000 litres

I'd go back to yout 3 pod filters and dose ST. Those big blues seem rubbish for the money. Constantly jiggling them and refills are a fortune.

Originally Posted by Alburglar

I'd go back to yout 3 pod filters and dose ST. Those big blues seem rubbish for the money. Constantly jiggling them and refills are a fortune.

With the chlorine, trihalomethane, and higher levels of metals you get from all that extra chlorine eating into the networks pipes, a 3 pod would be useless.

Still need the 3 big blues to take out the bulk if the chlorine and the chemicals dechlorinating fluid doesn't touch like pesticides, arsenic, etc...

Some tapwater is just plain poisonous for koi keeping,
If mine had been this high with my old pond I would have given up and not built my new one....

You should drill a well if it's that bad. Where I am, you don't need a permit. Dunno about other parts of the country.

Originally Posted by Alburglar

You should drill a well if it's that bad. Where I am, you don't need a permit. Dunno about other parts of the country.

the ground the house is built on is an old colliery and brick works... basically poisonous even plants and trees die in it
had to dig out the entire garden and transport in tonnes of new top soil but the subsoil is grey, coal, slag, brickbats, and lumps of reinforced concrete.

might have to move a couple of hundred miles away methinks

This probably doesn't work but I was wondering...

Could you not add the ST solution to the water (not sure how exactly as it'll be under pressure) to the mains water before the big blues?

That way they'd have a much easier job to do if all/most of the chlorine is removed.

I'm guessing this can't/shouldn't be done... but thought I'd throw the idea out there just in case.

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Originally Posted by Twhitenosugar

This probably doesn't work but I was wondering...

Could you not add the ST solution to the water (not sure how exactly as it'll be under pressure) to the mains water before the big blues?

That way they'd have a much easier job to do if all/most of the chlorine is removed.

I'm guessing this can't/shouldn't be done... but thought I'd throw the idea out there just in case.

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i had already thought of this,
you can't add anything direct to mains water breaches lots of water bylaws on contamination

the easiest way to do it would be to have a 'ball float valve' (was called a ball cock for 100's of years lol) and dose ST in a 1000 litre IBC to kill the chlorine and then pump the water through the big blues,
the carbon would then remove ST byproducts?
i can't remember what they are off hand so would need to look at mankey sankeys website for the chemical reaction to see whats left... mainly sulfates i think?
thats a lot of trouble, and i don't have room for a 1000 litre IBC unless i had it on the patio...missus wouldn't be too impressed

my Jebao 3 channel doser is set up now, and i bought a 5 litre can of kusuri dechlorinator for the first channel,
so i'll be dosing 10ml of dechlorinator 4 times a day direct to the pond to remove anything that gets past the big blues..
and i'll use one of the other two for bicarbonate dosing due to running recycle RO.

Originally Posted by Ajm

Completely lost !! Where the main man manky !!

Reminds me I really need to sit down and have a look at his courses .

Sent from my SM-G973F using Tapatalk

Sorry for the delay, I've been setting up my new Koi Nutrition course.

I can't find any research on toxicity to fish of EDTA (EthyleneDiamineTetraAcetic acid) but there are several datasheets warning of its hazards.

The way it can be hazardous is in its tendency to chelate (bind to and remove) metals that are essential in our bodies or fish bodies including calcium (Ca²⁺) and magnesium (Mg²⁺) especially with continuous exposure. In humans, unhealthily low values of calcium will cause weak bone structures and unhealthily low values of magnesium results in high blood pressure and risk of heart disease. There is no reason to suggest that this effect wouldn’t occur if fish were exposed to the long term presence of a significant level of EDTA in their water.

EDTA is added to soft drinks and some foods as a preservative but the levels must be so low that the harm it does by removing essential metals from our bodies won’t be great and our ability to uptake what has been removed will enable us to tolerate the small reduction.

OK, that’s the reasoning behind my answer to the question “How much EDTA to add to sodium thiosulphate to make a metal chelating dechlorinator?” which is “Dunno mate, some dechlorinator manufacturers may be adding very low levels as their secret ingredient so they can make claims about metal reduction but I use sodium thiosulphate and won’t be adding any”

I’m run off my feet teaching at the moment so I can’t do it myself but if anyone has the time perhaps they could ask a few dechlorinator manufacturers the simple question “Is there EDTA in your product?” and let us know if they get anything but waffle back!

Originally Posted by Manky Sanke

Sorry for the delay, I've been setting up my new Koi Nutrition course.

I can't find any research on toxicity to fish of EDTA (EthyleneDiamineTetraAcetic acid) but there are several datasheets warning of its hazards.

The way it can be hazardous is in its tendency to chelate (bind to and remove) metals that are essential in our bodies or fish bodies including calcium (Ca²⁺) and magnesium (Mg²⁺) especially with continuous exposure. In humans, unhealthily low values of calcium will cause weak bone structures and unhealthily low values of magnesium results in high blood pressure and risk of heart disease. There is no reason to suggest that this effect wouldn’t occur if fish were exposed to the long term presence of a significant level of EDTA in their water.

EDTA is added to soft drinks and some foods as a preservative but the levels must be so low that the harm it does by removing essential metals from our bodies won’t be great and our ability to uptake what has been removed will enable us to tolerate the small reduction.

OK, that’s the reasoning behind my answer to the question “How much EDTA to add to sodium thiosulphate to make a metal chelating dechlorinator?” which is “Dunno mate, some dechlorinator manufacturers may be adding very low levels as their secret ingredient so they can make claims about metal reduction but I use sodium thiosulphate and won’t be adding any”

I’m run off my feet teaching at the moment so I can’t do it myself but if anyone has the time perhaps they could ask a few dechlorinator manufacturers the simple question “Is there EDTA in your product?” and let us know if they get anything but waffle back!

Thanks Syd

I couldn't find much information on EDTA dosage rates either,
other than one from michigan koi's web site,
https://michigankoi.com/koi-college-pond-water/

and a safety data sheet on API's tap water conditioner that lists sodium thiosulfate and EDTA as ingredients.
and gives the weight ratio percentage of the dry ingredients but not how much water they are diluted into as:
30.2% sodium Thiosulfate and
9.8% EDTA tetra soduim salt

https://www.apifishcare.com/pdfs/pro...data-sheet.pdf

but due to the lack of information about EDTA, and potential l hazards of use.
i decided that would be far easier to stick with safe Sodium Thiosulphate or buy a liquid dechlorinator to include metal detoxifying.

Don't bother with Kusuri's Dechlorinator...
it only contains sodium thiosulfate and water

no metal chelating EDTA.
sent back....

I've done some more investigation of dechlorinator ingredients after finding most only contain sodium thiosulfate but claim to detoxify metals.
So they are claiming sodium thiosufate as the 'metal detoxifier'.

after scouring the internet i found some papers concerning sodium thiosulfate and EDTA for metal detoxification.
admittedly it's marine sea urchin larvae but as they are far more sensitive to copper and heavy metals than fish,
it shows how well EDTA works by comparison to Sodium Thiosufate as a metal detoxifier
showing Sodium Thiosufate only has a reasonable reduction of
Ag+ (silver ions)

and EDTA has a dramatic effect in reduction with
Cu( copper ions)
Zn (zinc ions)
Pb (lead ions )


https://pdf.sciencedirectassets.com/...cb4f773b&cc=gb


Sodium Thiosufate Metal Reduction

this graph shows the death rate of urchin larvae in the presence of different strengths of thiosulfate in metal solutions.




EDTA Metal Reduction

this graph shows the death rate of urchin larvae in the presence of different strengths of EDTA in metal solutions.

Originally Posted by davethefish1

Don't bother with Kusuri's Dechlorinator...
it only contains sodium thiosulfate and water

no metal chelating EDTA.
sent back....

You're forgetting the 0.1% blue dye

So where do we get a dechlorinator with EDTA in it to detoxify metals in tap water..

the only product i have found that states it in it's MSDS material safety data sheet is API's Tap Water Conditioner.
under the section composition of mixtures it lists sodium thiosulfate, and EDTA tetra sodium salt.
and is listed as corrosive and 'dangerous to health'

https://apifishcare.com/pdfs/API%20T...1625170479.pdf



but if you look at API's 'Stress coat' which also says 'makes tap water safe' 'removes chorine, chloramine, and detoxifies heavy metals'.
it doesn't list any ingredients in it's safety data sheet, just ' ingredients determined not to be hazardous'....

so considering tapwater conditioner has to list the ingredients and gets a 3 on the blue warning diamond 'dangerous to health'.
it would be fair to assume that stress coat plus has no sodium thiosulfate or EDTA in it.....

https://apifishcare.com/pdfs/STRESS%20COAT%20SDS_1624280674.pdf



API's Pond Stress coat has a similar MSDS sheet stating 'ingredients determined not to be hazardous'
but on the back of the tub lists ingredients as 10% aloe vera 1% PVP (Polyvinylpyrrolidone (binder)....

https://apifishcare.com/pdfs/POND%20STRESS%20COAT%20SDS_1624280840.pdf

Originally Posted by g mac

You're forgetting the 0.1% blue dye

do you mean the 'Magic' blue dye that also detoxifies metals?