Importance of dechlorinator for tapwater question

[Pathos]

Hello,

It is often suggested to use a dechlorinator when doing waterchanges (some say during/some say after) fishless cycling. This in order to not kill off nitrifying bacteria in the tank. These bacteria only live in water and are therefore initially introduced via tapwater. Chlorinated tapwater, in many cases. How is it that the chlorine in tapwater doesn't kill off these bacteria in the water pipes between the treatment plant and my faucet? This appears to contradict itself.

Both cannot be true. Please point out my error, here. Thank you!

 

[Rbishop]

It's the chlorine or chloramine that can not only have an affect on some bacteria, but also on the fish themselves.

 

[FreshyFresh]

My head hurts..

Good question!

 

[OrionGirl]

Yep. Dechlorination is for the fish/plants more so than the bacteria and microfauna. There's a growing body of evidence that the primary nitrifiers aren't bacteria, but rather archaea, as well.

 

[MChambers]

Hello,

It is often suggested to use a dechlorinator when doing waterchanges (some say during/some say after) fishless cycling. This in order to not kill off nitrifying bacteria in the tank. These bacteria only live in water and are therefore initially introduced via tapwater. Chlorinated tapwater, in many cases. How is it that the chlorine in tapwater doesn't kill off these bacteria in the water pipes between the treatment plant and my faucet? This appears to contradict itself.

Both cannot be true. Please point out my error, here. Thank you!

My guess is that the chlorine (or chloramine) in tap water kills most, but not all, of the bacteria and archaea.