Chlorine In Tap Water.

[Steffyboy]

I've been talking to a good few different people on forums etc about when they do a weekly water change and a lot of them are not using dechlorinators and just filling up and leaving.
They say they've been doing this for years and have never had any problems.
I know about all the problems that chlorine can cause with regarding fish and i religiously use Aqua One ammonia and chlorine neutralizer.
Does anyone do the same as these other people and not use any chemicals and what's your thoughts on not using them?

 

[TallTree01]

Nope, I use them.
Sounds pretty irresponsible. Where are they getting their water from? Perhaps it's a non chlorinated source like a well or somehting?

 

[fluttermoth]

Personally I always use a dechlorinator; it's so cheap, especially if you use a concentrated one, that it seems silly not to.

On the other hand, it is true that for water changes of around 50%, or less, you don't need one. The level of chlorine in tap water is there to kill the odd, lose, floating bacteria in the water supply, and half of that concentration is not enough to knock out a well established bacterial colony like the ones we have in our filters, or to adversely affect your fish.

I myself have known very many successful fishkeepers and breeders who don't dechlorinate.

Pretty obviously, you should always use dechlor in newly set up tanks, where the colonies aren't as robust, and for fry tanks.

It might be different if you have chloramine in your tap water; I don't know enough about it to be able to say.

 

[This Old Spouse]

Even if I didn't have chlorine in my tap water, which I do, I'd still use Seachem Prime or another high-end product because it also eliminates several other metals and other nasties in tap water.

 

[coolie]

The problem is not chlorine, it's chloramine. If you live in the UK (and US mostly I think now) the chloramine is the problem.
 
Chloramine does not pass your gut wall and into your blood stream as a human, but with fish, it does pass straight through the gills into their blood and is toxic.
 
Also how toxic it is and the effect depends on the particular breeds you keep. Live foods die in under 24 hours in un-dechlorinated water. Some sturdy fish will be fine in it.
 
It is also pervasive and long-lived taking a couple of weeks to disperse, rather than 24 hours. I also use the concentrated brand mentioned above which lasts for years.
 
The individual water areas in the UK freely make available their water analysis and you can normally download them, and they are really interesting (if you like that kind of thing and have loads of time on your hands).

 

[TwoTankAmin]

The danger is normally to fish before bacteria. But as with everything else in this hobby, there are very few hard and fast rules.
 
Chlorine is a gas and wants to be a gas. A bucket full of chlorinated water will out gas the chlorine. Agitate and it does so faster. So if one has only low level chlorine in their tap is is entirely possible it will dissipate during filling and filtration to out gas before it can harm anything.
 
As noted chloramine is different. It wont kill the bacteria but it will harm fish. Nor will it out gas rapidly. it is basically chlorine and ammonia combined. When it finally breaks down you get chlorine and ammonia. This is why modern dechlors now contain ammonia detoxifiers.
 
All that said where is the danger of not using dechlor even when you know what is in your tap and at what levels. First, as noted, different species are differently sensitive. So you may not pay attention and put the wrong thing in. But more importantly, hard as the water companies try, sometimes things go wrong or they change. One day they go from using lower level chlorine to treating with a higher level of chloramine, you are not aware of the change and the result is floating fish. Or there is a bad storm and this lets nasty bacteria into the water system which responds by upping the amount of chlorine temporarily to handle this. Oops, more floating fish.
 
So while low levels of chlorine or chloramine may be something one could ignore in certain cases, I would never recommend it relative to the fish and critters.
 
Just as an aside, research has been done experimenting with low levels of chloramine to treat certain external diseases of fish. Results have been promising in this respect.

 

[Blondielovesfish]

I remember reading somewhere that some fish are intolerant of dechlorinaters (native New Zealand specie are one, probably because they're wild caught) so the owners have to do more little water changes, which IMO isn't always the best idea, because, if say you had a large ammonia or nitrite spike, you wouldn't be able to reduce the spike very fast. For this reason, I gave up on the thought of doing a Native New Zealand Biotope.
However, many people do it and as long as they're small water changes, the fish (and bacteria) don't seem to be effected.

 

[coolie]

Blondie do you know which brand or why these fish were sensitive to dechlorinators. As far as I know chloramine removal releases ammonium and ammonia and thiosulpahte dechlorinator releases sodium and chloride ions all in extremely small amounts?

 

[Blondielovesfish]

Hang on, I'll find a thread where I shared the information. 
 
It's this thread here, it's mostly about the person saying about dechlorinaters, not really of fish being intolerant but it relates.
 
I'm not completely sure why they're intolerant of the dechlorinaters but I think is has something to do with them being wild caught and not encountering dechlorinaters in the streams.