Dechlorinator: To Use Or Not To Use?

[RookieAqua]

Hi I am new to the fourm and kinda new to fish keeping so here is my problem:

I have had very mixed reviews regarding dechlorinators/conditioners. I have 2 friends locally that have been keeping fish for 20+ years and never used a dechlorinator/conditioner and thier fish are great. They let the water stand for a minimum of 24 hours and away they go. On another fourm everyone says you MUST use it or your fish will die. Here is my situation:

I have double and triple checked with the water company they DO NOT USE chloramine in the water. They ONLY USE chlorine which I know will evaporate out. I had a tank a few years ago (4 or 5 to be exact) I used dechlorinator then started a fishless cycle, did the final water change using dechlorinater and added fish they all died within a few hours (roughly 5 hours I think). Ok thought I had done something wrong with the fishless cycle. Dumped everything in the tank and started over (this time with out dechlorinator) confirmed that my tank was cycled added the fish they were great untill my first water change. Added water using dechlorinator all the fish died with in hours. Please note that I had hardy fish (zebra danios) and prior to death showed no signs of illness. Ok so I gave up I figured I just wasn't meant to have a fish tank. Well I thought I would try again. So far everything has been fine, I used dechlorinator when I set up the tank let it sit for 72 hours then started the fishless cycle process the cycle completed about 3 week later (had some borrowed media), and then added fish - no further dechlorinator at this point the fish are doing great.

Basically do I need to use water conditioner? I was on another fourm and they chastized me for not using it. But as I said MY WATER DOES NOT CONTAIN CHLORAMINE. My only other concerns is the city did say there could be trace amounts of Copper and/or Lead in the water (my water through my pur filter test 0ppm for copper and chlorine). I am really really nervous about using water conditioner as I have had dead fish with in hours of using it in the past, and yes my doses were correct, and yes I treated the water prior to putting it in the tank, I never treated tank directly from the bottle of conditioner.

I am very confused about this issue and extrememly nervous about using conditioners. My only goal in this endevour is to have healthy live fish, I really don't want to come into a tank full of dead fish a few hours after a water change, been there done that . Any advice you could give would be greatly appreciated.

Additional FYI:

previous tank 29 US gallon fishless cycle - 8 zebra danios

Current Tank 12 US gallon fishless cycle - 4 zebra danios

Thanks

 

[drobbyb]

I highly doubt it was the dechlorinator that did it. I have used dechlorinator for 17 years and have never had that problem. The only problem I had was when I didn't use it and my fish died within hours.

The only thing I can think of is if you massively overdosed the tank with it.

 

[lalo99]

Are you matching ph and temp when doing a water change? A large change in ph will kill fish very fast. this is important to do for each water change. You should also know the KH (carbonaate hardness) and GH ( general hardness) of the water. You should know these number for both tank and tap.

You are correct that chlorine will dissipate from water over time. Chlorine is a gas and is very unstable in water. I would however, run a pump in the water, Rather than just let it stand overnight. The more surface area there is, he faster the chlorine can dissipate. I use a declorinator called prime. It also helps detoxify ammonia and nitrites. One thing to keep in mind is, what if you need to do an emergency water change? If you don’t have time to let the water sit you would have a problem with the chlorine in the water.

 

[Nick16]

if im doing a w/c of less than 25% then i dont use any, if its more i use such tiny amounts. on my 120L i did a w/c earlier and forgot about dechlor and surprise surprise they are fine. If you keep highly sensitive fish then yes its good to use it. i do use pond dechlor though, much cheaper!

 

[Tolak]

http/www.fishforums.net/index.php?showtopic=161413 Post #19

 

[drobbyb]

Interesting. So basicailly, if you don't dechlorinate your water, you may be adding to an existant problem, just like antibiotics are contributing to staph infections in hospitals (I lost my mother to MRSA a few years back, so this topic still stings a little). Am I way off base here?

 

[Tolak]

Not so much adding to the problem, as using the water company's problem to your benefit. The bacteria in the water supply are living off of the ammonia split from chloramine. While you may be adding these to the local waste water system in some small amount, they are probably non-existent by the time the water makes its way to the supply system. Even if they did, by being in your tank from the water supply they are already in the supply system.

 

[drobbyb]

Oh ok. I understand. Thanks Tolak!

 

[Assaye]

Water conditioners often do much more than de-chlorinate. Many add aloe vera, some detoxify ammonia and nitrites, and most remove heavy metal residues. I would always use a water conditioner unless I know exactly where my water is coming from and that it is clear of chlorine, chloramine and heavy metal residues.

Water conditioner shouldn't kill fish, even in larger doses than recommended. There are so many things that go wrong in a fish tank - I doubt de-chlorinator was the culprit, unless there was something drastically wrong with the make/batch you were using.

If you want to be super safe, and not have to use water conditioner, try RO water.

 

[waterdrop]

I agree with the others, I don't think dechlor was likely to be your problem.

There happens to be another thread currently on the same topic and I commented there:

Other dechlor thread!

I recommend you use a good conditioner like Prime and consider transitioning to pond dechlor or even your gas-off process (just refill the containers after the weekly water change and let them stand until next week's change, but be sure to watch for any announcements of your water authority switching over to chloramine. Good conditioner is so cheap to use its just good insurance) after the tank has matured to one year or so. After a year the biofilms and autotrophic colonies will be much more mature and stable. Size of water change matters too, many here feel that mature tanks receiving less than a 15% water change don't need dechlor.

~~waterdrop~~