How Important Is It To Dechlor When Fishless Cycling?

[locust267]

Hi, as the question in the title suggests I was just wondering how important it is to dechlor the water when no fish are present?

I've heard that chlorine evaporates within 24-48 hours so not sure why you would need to dechlor the water at this stage unless it's for other harmful metals which wont disappear before the fish are added?

 

[OldMan47]

It is absolutely critical to dechlorinate water before it goes into a tank that has anything living in it. The main thing you do during a fishless cycle is try to get a bacterial colony to live in your filter. The water company is adding chlorine to kill bacteria so that your water will be safe for people to drink but that same chlorine will kill the colony that you are trying to establish. It is also the reason that we never clean filter media using tap water. If you use straight tap water to clean filter media your cycle needs to start all over again.

 

[locust267]

But say you were to fill the tank and leave it to rest for 48 hours allowing the chlorine to evaporate before adding any ammonia would it still start to kill off the bacteria from this time onwards?

 

[freddythefish]

I/m not sure it does evaporate...where is this infor from?

 

[Rooster]

Chlorine DOES evaporate.... cloramine does NOT, unless you KNOW your water specs from the tap - then play safe and dose it anyway.... must cost a few pence, so why cut corners ?

 

[OldMan47]

I will agree with both rooster and locust. Back a half century ago when I started keeping fish we always treated tank water by letting it sit out for a day or two before using it. There was no dechlorinator available at the time so it was all we could do and it worked nicely. As time has passed, the water treatment processes have "progressed" to the point where many treatment plants now use chloramine. They use it because it lasts much better in the water that is in the pipes under the street than the old chlorine used to. That makes it better at fighting off bacteria getting to you at the tap. The trouble is it will basically not be removed by letting the water stand out like chlorine would be.

 

[locust267]

Ok cheers, was just intrigued to find out why, wasn't saying I was gonna try it.

How honest are water companies about the usage of chloramine? Do they all use it now?

 

[pastabake]

I agree that its good practice to always use dechlor if your water is treated.

Though the interesting thing is where does the AOB & NOB's come from? If they, as some suggest, come in with the tap water then neither chlorine nor chloramine must be much of a problem to them.

Locust267 - Water companies are pretty honest about such things. From what I read chloramine is pretty much the norm for the States but in the UK its use is still pretty patchy, so its always best to give them a ring.

 

[lizjamie]

I can contribute that one of my major setbacks in fishless cycling was due to doing a water change to reduce nitrite and forgetting to decholiinate. I was back to square 1 and lost 4 weeks of effort!
So it might be best ot just to be on teh safeside

 

[Esfa]

Chlorine DOES evaporate.... cloramine does NOT, unless you KNOW your water specs from the tap - then play safe and dose it anyway.... must cost a few pence, so why cut corners ?

apparently, there's is a thought that the bacteria feeds of the "-amin", allowing the chlorine to disperse.

 

[OldMan47]

The bacteria don't come in with treated water. Any bacteria in that water are dead. If you don't know where bacteria, mold, etc. come from, try leaving a slice of bread or a piece of fruit laying out on the kitchen counter for a week or two. You won't know where that comes from either but it won't look ready for me to eat any more. Bacteria are not rare or hard to find. What we do is establish conditions that let them multiply readily and then we take the credit for them being there.

 

[waterdrop]

Usually water companies, especially if you get put through to the lab people, are quite up-front about their techniques.

Chloramination has been "the latest thing" for a number of years and many of them are quite proud of it if they have moved to that technique. There are certain extremely small cancer risks potentially associated with chlorine use and chloramines seek to lower that risk even more. Unfortunately, some of the very latest studies have reversed a bit I believe and potentially will call into question certain aspects of the chloramine, sigh, but that's a different story and I can't remember where I read it anyway!

The number of water authorities who use chlorine techniques vs. those who use choramination techniques is quite varied and unpredictable I believe. You can't really make geographic assumptions, you have to just find out directly from the people who are responsible for your water source.

I agree with oldman47, by the way, that chloramination is common enough now and both techniques even have changed enough that none of us fishkeepers should be going without water conditioning for our larger changes and replacements. Its just to cheap and easy not to be safe.

~~waterdrop~~

 

[Esfa]

The bacteria don't come in with treated water. Any bacteria in that water are dead. If you don't know where bacteria, mold, etc. come from, try leaving a slice of bread or a piece of fruit laying out on the kitchen counter for a week or two. You won't know where that comes from either but it won't look ready for me to eat any more. Bacteria are not rare or hard to find. What we do is establish conditions that let them multiply readily and then we take the credit for them being there.

If that was a reply to me, then i meant the bacteria in the filter feeds off the "-amine" part of chloramine, leaving just chlorine.

 

[OldMan47]

Esfaq, no disrespect was intended. You are somewhat right in that when dechlorinator breaks down chloramine, it leaves behind some ammonia. That ammonia can contribute some of the ammonia needed to start to grow your bacterial colony. My water tests at almost 1 ppm from the tap of ammonia. I thought I was reading that the live bacteria comes from tap water which struck me as nonsense but I tried to say it a little nicer.

 

[pastabake]

I take it you've done tests?

Only 1% of bacteria in soil or water may be culturable ... so it really depends upon the assay used to determine levels of bacteria in tap water. If the test are only for coliform or other known and culturable pathogens ... and why would they test for harmless bacteria? Actually it look like they don't, they test for indicators ... so our NOB's and AOB's may simply be ignored as being irrelevant to human health.

If you're really interested in this then take a look at this - hxxp/en.wikipedia.org/wiki/Bacteriological_water_analysis

The common feature of all these routine screening procedures is that the primary analysis is for indicator organisms rather than the pathogens that might cause concern

In the UK the limit is 100 bacteria per mililitre, so while potentially insignificant - if this is the true count - its still enough to form a colony... 12.5 million in a 125ltr aquarium.

That aside -

Between 1993 and 2003, there were 4,000 officially recorded incidents of waterborne disease in Britain. The real figure is likely to be far higher

Now correct me if I'm wrong but AOB's and NOB's don't pose a human health concern.

Anyway, as I stated some people do assert that seed bacteria may come from tap water, I personally choose to have an open mind as until some definitive research is done its pointless to make assertions either way.