Chlormine Spikes, are they real?

[Conan]

I have been advised by my LFS and by an article on aquariumscience.org to use 5X the regular dosage of dechlorinator to treat the chloramine in my water because they say that municipal water supplies, like the one in my city, will spike the chloramine (or chlorine) dosage in response to spring runoff, leaks, storms or bacteria testing without alerting anyone. Does anyone know if this actually happens?  It would be really nice to get some clarity on this topic.

[MWilk]

Dechlorinator is safe in massive overdoses. To save money, you could always just test for chlorine. 

[Tony s]

On 9/5/2024 at 12:04 AM, MWilk said:

Dechlorinator is safe in massive overdoses

To some extent this is true. But I’ve seen a betta actually hide from a 5x dose and sit there shaking from the chemicals.  So @Conan testing would probably be best. They probably don’t do it very often. And your water source may actually publish when it’s going to do that. Problem is I have no idea where to send you to find out.

[mynameisnobody]

I’ve been dosing normally for years and never had a problem. Don’t overthink it and if you do, test your water.

[TOtrees]

There's a lot of assumptions that underlie this idea. First question for me, are you sure you're in a municipality or region that uses chloramines? Not all do. 

Other suggestions:

Have you accessed the water quality report for your municipality or area? They're usually available, with a bit of digging. It might not tell you exactly what you want to know, but it will likely eliminate some unknowns. 

Have you tried to reach out to or connect with someone in the water branch of your municipality? 

[Markp2483]

Occasionally I see big spikes in chloramine in my water. It’s cost me fish particularly if I have a hospital tank that’s not really established .
 

I’m in Southern California and I know they use chloramine.  I’ve tested it as high as 4.0 out of the tap with Hanna ammonia checker.  Trying to talk to the water municipality didn’t have any results.
 

I’ve switched to using a carbon water filter  to pretreat the water before it goes into the tank. But before that I used dechlorinator. The trick I found is to treat  the tapwater with dechlorinator in a separate container and run an airstone for 15-20mins before adding it to the tank. A bonus advantage is you can match the temperature to the tank water in the container which also helps to reduce stress

[johnnyxxl]

On 9/4/2024 at 11:59 PM, Conan said:

I have been advised by my LFS and by an article on aquariumscience.org to use 5X the regular dosage of dechlorinator to treat the chloramine in my water because they say that municipal water supplies, like the one in my city, will spike the chloramine (or chlorine) dosage in response to spring runoff, leaks, storms or bacteria testing without alerting anyone. Does anyone know if this actually happens?  It would be really nice to get some clarity on this topic.

It does happen.  I lost my whole tank years ago because of this.  The municipal changed to chloramine during storm caused flooding and didn't tell anyone.  Not even the office personnel knew because I called to ask, before treatment for the chlorine.