Sodium Thiosulphate

[Stimo]

Was wondering if anyone out there uses this to De-chlorinate their tap water before adding to tank?

 

[bodge99]

Hello,
 
Yes, I've used exactly this for years..
 
See http/www.cnykoi.com/calculators/calcdechlor.asp
 
Bodge99

 

[Stimo]

thanks
what would the ppm of chlorine be in tap water roughly?

 

[bodge99]

Hello,
 
You would need to contact your water supplier for an accurate figure.. DEFRA state "Typically water companies keep the level of residual disinfectant in the form of free or combined chlorine to 0.5 mg/l or less"
 
I assume 1ppm as there are no chloramines in my supply. If there was, I would work to either 2 or 3ppm chlorine.
 
It's actually very hard to overdose with sodium thiosulphate.
 
I use one of these http/www.ebay.co.uk/itm/Mini-0-01g-100g-Digital-Jewelry-Pocket-Scale-Gram-Oz-/191043516441?pt=UK_BOI_Electrical_Test_Measurement_Equipment_ET&hash=item2c7b14b819 to weigh the crystals.
 
You can calibrate this type of electronic scale with 20 x 20p coins (20 coins weighs exactly 100g i.e. 20 x 5g).
 
If you work through the stock solution calculator and have a play with some crystals and an electronic scale, you will find that you will be working to a "fraction of a crystal" when making up "sane" volumes of stock solution.
 
Just "round up" to the next "whole crystal". You'll see exactly what I mean when you get there.
 
At the risk of upsetting any chemical engineers here, I don't use distilled water to make up stock solution. I use cooled, previously boiled water.
 
I dispose of any unused stock solution after 6 months and make up fresh.
 
500g of sodium thiosulphate is about £5 on Ebay. This quantity will last you years.
 
Bodge99

 

[Stimo]

Thanks for this
i was just looking at a post and wanted to run it past you to see what you thought about it.
The old boy on there said to mix 500g of sodium thiosulphate with 1 gallon on water and keep that as your solution then when changing water to add 2 drops of solution per gallon of water , does this sound about right to you?
also there was no info on how big a drop was if you could help on that?
 
Thanks again for your time on this.

 

[bodge99]

Hello,
 
I use a medicine syringe.. you can get these cheaply from your local chemist.
 
One of the dilutions I use is this..
 
For 500ml of stock solution add 7(.011)g of sodium thiosulphate. This is calculated for 1ppm chlorine.
 
Dissolve the crystals in 500ml of water.. The solution is now ready for use.
With this concentration use 5ml of stock solution for every 20l of water changed.
 
Have a play with the numbers on the stock solution calculator on http/www.cnykoi.com/calculators/calcstdose.asp
until you find volumes/amounts that suit the way that you want to work...
 
Hope this helps.
 
Bodge99

 

[Stimo]

Thanks for that calculator i've given it a go so will run it past you to see if i have done it correctly then i won't have to bother you again (hopefully

)
 
i want to make 500ml of solution .
2.5ml dose to treat 10l of water with chlorine at 1ppm.
so i need to add 6.969g of sodium thiosulphate?
hows that sound?
 
Also would i be safe in assuming the chlorine level was at 2ppm just to make sure i've neutralized it or would it be best to work/find out exactly how much is present in my tap water and go from there?
 
Thanks

 

[bodge99]

Hello,
 
Yes, I get the same figures as you.
 
You should be perfectly OK calculating for either 1 or 2ppm.
You would need massively greater concentrations to actually overdose. You are aiming to dose a sufficient amount to do the job with a little "spare overhead", if you see what I mean. Enough to cope with any variations in the chlorine concentration in the water.
 
If you want "peace of mind", then by all means try emailing your water supplier and see what they have to say.
I would mention that you are a fish keeper and you are trying to determine optimal dechlorination chemistry etc.
 
I'd be interested to hear exactly what they say.
 
BTW, it's never a problem discussing this sort of stuff.. I'm very interested in other peoples opinions and experiences.
 
Good luck.
 
Bodge99

 

[Stimo]

just thought i'd let you i received a letter from the water company and said the average results for chlorine in my area is 0.17mg/l same as ppm.

 

[Stimo]

 

[bodge99]

Hello,
 
Interesting.. thanks for posting this.
 
With these figures, I would work to 2ppm.
 
I understand that some people "sniff" their (clean) water and up the dechlorinator dosage a little if the chlorine smell is stronger than usual.
 
Bodge99.

 

[Stimo]

Not a problem.
my sense of smell isn't great at the best of time
i will work to 2ppm then.
i'm yet to purchase the thiosulphate yet , will keep you posted when i do.
 
Thanks again

 

[bodge99]

Hello,
 
When you obtain your sodium thiosulphate, store it in an air tight container, out of direct light.
 
In my youth, I used this stuff as a major ingredient in darkroom (photographic) fixer... It's also known as "hypo"
See  http/en.wikipedia.org/wiki/Photographic_fixer
 
Good luck.
 
Bodge99

 

[Stimo]

Thanks will do that.
Ordered last night went for 200g see how I get along with that first.
So when doing your aquarium water changes is this all you use or is there something else you recommend adding as well?
My aquarium is planted with Java fern java moss and sag

 

[bodge99]

Hello,
 
I don't use anything else at all.. Never had any problems...
 
Good luck!
 
Bodge99