Thread: Does ST remove Chloramines and metals or just Chlorine?

Does anyone know?
thanks Steve.

I think it will remove the Chlorine element but not the ammonia that's in Chloramine

That's correct.

To add some further information for anyone interested:

Chloramine consists of ordinary chlorine plus ammonia so, if water suppliers wish to use chloramine, they first add chlorine to the supply as normal and then simply add ammonia which combines with the chlorine to make chloramine.

I can do the molecular weights of each if you want the exact proportion but, in round numbers, chloramine is made of two parts chlorine and one part ammonia. Any form of dechlorination based on sodium thiosulphate (i.e. proprietary liquid dechlorinators or sodium thiosulphate crystals or a premade stock solution) will remove the chlorine but leave the ammonia component. Activated carbon purifiers will also remove chlorine or chloramine but I don’t know of any purifiers that also remove the ammonia component of chloramine.

There’s no need to worry about the amount of ammonia left behind because it's only a low level and will soon be removed by the biofilter. Sensitive people can taste chlorine or chloramine at levels above 0.8 mg/L so this is the highest normally added to domestic water supplies.

Even a 100% water change with the highest normal level of 0.8 mg/L chloramine in the supply will only leave 0.25 mg/L ammonia in the pond after it had been dechlorinated by sodium thiosulphate or a proprietary dechlorinator based on sodium thiosulphate. That isn’t ideal but is within tolerable limits, even at a high pH, and this will be quickly removed by the biofilter.

The level of ammonia left behind after a more normal water change will be diluted by the volume of water already in the pond so it will only be at a trace level. E.g. the ammonia level in the pond after a 10% change will be 0.025 mg/L and a 20% change will only leave 0.05 mg/L. These levels are only detectable by the best electronic testers and, as I said above, they will quickly be removed by a working biofilter anyway.

Originally Posted by Manky Sanke

To add some further information for anyone interested:

Chloramine consists of ordinary chlorine plus ammonia so, if water suppliers wish to use chloramine, they first add chlorine to the supply as normal and then simply add ammonia which combines with the chlorine to make chloramine.

I can do the molecular weights of each if you want the exact proportion but, in round numbers, chloramine is made of two parts chlorine and one part ammonia. Any form of dechlorination based on sodium thiosulphate (i.e. proprietary liquid dechlorinators or sodium thiosulphate crystals or a premade stock solution) will remove the chlorine but leave the ammonia component. Activated carbon purifiers will also remove chlorine or chloramine but I don’t know of any purifiers that also remove the ammonia component of chloramine.

There’s no need to worry about the amount of ammonia left behind because it's only a low level and will soon be removed by the biofilter. Sensitive people can taste chlorine or chloramine at levels above 0.8 mg/L so this is the highest normally added to domestic water supplies.

Even a 100% water change with the highest normal level of 0.8 mg/L chloramine in the supply will only leave 0.25 mg/L ammonia in the pond after it had been dechlorinated by sodium thiosulphate or a proprietary dechlorinator based on sodium thiosulphate. That isn’t ideal but is within tolerable limits, even at a high pH, and this will be quickly removed by the biofilter.

The level of ammonia left behind after a more normal water change will be diluted by the volume of water already in the pond so it will only be at a trace level. E.g. the ammonia level in the pond after a 10% change will be 0.025 mg/L and a 20% change will only leave 0.05 mg/L. These levels are only detectable by the best electronic testers and, as I said above, they will quickly be removed by a working biofilter anyway.

Thank you very much MS and Gmac,
If i have understood this correctly my 3 stage dechlorinator and top ups with a stock solution of ST as per your dilution rates from your website should take care of any Chlorine in the pond and Chloramines? Physical ammonia levels are showing as zero via Colombo and API tests, is there any way that the pond water could still have Chloramines levels still which could be the cause of some flashing? All parameters are spot on....i do not know of any way to test for chloramines? to add PD4 tablets are showing zero colour reaction to the pond water but bright pink when testing the tap water....

If the DPD4 test is showing no trace of colour (assuming the test has been done as I describe on my website) then there is no chlorine or chloramine in the water.

Thank you Manky Sanke.....

Originally Posted by MrHudson

Hi mate,

i always use 5ml of sample water in a test tube, was told the other day it should be 10ml? Have I been over or under testing?

10ml of water and look down through the top of the tube placed on a white background.

Using only 5ml of water will make the DPD4 tablets twice as strong I think you'll find

Just a thought here but may be worth getting Manky Sanke's confirmation, if you only use 5ml of water and the water doesn't go pink instantly surely that could mean there's even less chlorine in the water? Not sure if it works like that so get Manky's thoughts first.

Originally Posted by MrHudson

This is what I’ve been thinking. That’s it’s not exactly a bad thing. But I have no clue with chemistry

I know it's definitely meant to be 10ml but the 5ml theory was just an uneducated suggestion that needs confirmation

Excuse my sudden unannounced disappearance from this thread, I succeeded in breaking my hip on the 12th which meant I had to have a Total Hip Replacement and I've only just been allowed back onto my PC today

Anyway, the reason I didn't specify a sample amount was because, with a lesser the amount (e.g. 5 ml), the reduced volume and shallower depth of water in the tube will make any colour change appear "brighter".

On the other hand, if a larger sample size is used (e.g. 10 ml), any colour change will be more diluted by the greater volume and will be less "bright" but the depth in the tube you would look through will be greater so that will compensate for the diluted colour change.

So, in practice, it don't make bugger all difference.

Originally Posted by Manky Sanke

Excuse my sudden unannounced disappearance from this thread, I succeeded in breaking my hip on the 12th which meant I had to have a Total Hip Replacement and I've only just been allowed back onto my PC today

Anyway, the reason I didn't specify a sample amount was because, with a lesser the amount (e.g. 5 ml), the reduced volume and shallower depth of water in the tube will make any colour change appear "brighter".

On the other hand, if a larger sample size is used (e.g. 10 ml), any colour change will be more diluted by the greater volume and will be less "bright" but the depth in the tube you would look through will be greater so that will compensate for the diluted colour change.

So, in practice, it don't make bugger all difference.

Thanks for the confirmation

Sorry to hear about your hip, sounds nasty!!!

Hope you recovery ASAP but at least you have still got your sense of humour

Hope you have a good recovery Syd,was wondering what happened to you.
Take care of yourself.

Make a speedy recovery Syd.

Sent from my Pixel 4a (5G) using Tapatalk

Originally Posted by Manky Sanke

Excuse my sudden unannounced disappearance from this thread, I succeeded in breaking my hip on the 12th which meant I had to have a Total Hip Replacement and I've only just been allowed back onto my PC today

I hope you have a speedy recovery Syd

Hope for a speedy recover Syd, take it easy!