Do I need dechlorinator?

[jonnyc88]

The below is from my local water authority:

The average chlorine concentration for this Public Water Supply Zone from January 2020 to March 2020 was <0.05 milligrammes per litre free chlorine and 0.680 milligrammes per litre total chlorine. This drinking water supply is chloraminated.

Appreciate this is for Jan-Mar 2020 but based on those numbers do I still need to add dechlorinators?

 

[kwi]

Yes.
Chlorine is a strong oxidant and can be lethal to most fish at level between 0.1-0.3 ppm. Although is its best to maintain levels below 0.001 to 0.003 ppm as health issues can arise in aquatic systems.

 

[seangee]

Yes you do. As your supplier uses chloramine you always have to use dechlorinator. Leaving it to stand will not clear the chlorine.

 

[jonnyc88]

0.5ppm and up is toxic to fish, so yes.

Thanks, that's what I thought too.
I'm a bit confused by the numbers. What is free chlorine?

 

[jonnyc88]

Yes you do. As your supplier uses chloramine you always have to use dechlorinator. Leaving it to stand will not clear the chlorine.

Ah, you must've seen my other thread. I'm surprised by the recommendation from eSha regarding dechlorinating.

 

[Essjay]

It is possible that in the Netherlands where eSHa is based that chloramine is not used, only chlorine.

 

[kwi]

Thanks, that's what I thought too.
I'm a bit confused by the numbers. What is free chlorine?

I actually edited my post, toxicity levels are lower.
Free chlorine is how we know enough chlorine was added to water to make it potable, which is why it is reported. We're concerned with the total chlorine.

 

[jonnyc88]

It is possible that in the Netherlands where eSHa is based that chloramine is not used, only chlorine.

I suppose so. I will continue using Prime during water changes and carry on as advised by you