I contacted my water company regarding chlorine and this was their response

[Herefishie]

I wrote to my local water department asking if they periodically flush with chlorine as I have heard some cities do. I have never registered any chlorine in my tapwater. This was, in part, their response. I'm not a scientist so I'm wondering if this is a super low amount of chlorine and that's why I never have to treat my water?
"We received your inquiry. We don't use chloramines but we do chlorinate the water.  Chlorine residuals in the distribution system range from 0.3 - 1.2 mg/L.  The system isn't periodically flushed with chlorine, there is a chlorine residual in the system."

[T. Payne]

Well the good news is they don't use chloramines, which is a chemical that must be treated for. Chlorine can be gassed off through aging and aeration.

[Herefishie]

On 5/6/2024 at 1:32 PM, T. Payne said:

Well the good news is they don't use chloramines, which is a chemical that must be treated for. Chlorine can be gassed off through aging and aeration.

Thank you for this response. I do put my tapwater in gallon milk jugs and let them sit for a few days before I use them so I guess I'll just keep doing the same thing. Again, thanks for the insight. 😀

[Lonkley]

I know you CAN gas off the chlorine. But why not just use tap water conditioner.  A bottle is like less than 10 dollars and im still on my bottle from 2 years ago.  I mean the dose is so tiny and it may take care of other things. Im not even talking prime, just plain api tap conditioner.  I mean I guess some people dont want to use chemicals but its like literally a few ml on water than has already been chemically treated.

 

[Herefishie]

On 5/6/2024 at 2:19 PM, Lonkley said:

I know you CAN gas off the chlorine. But why not just use tap water conditioner.  A bottle is like less than 10 dollars and im still on my bottle from 2 years ago.  I mean the dose is so tiny and it may take care of other things. Im not even talking prime, just plain api tap conditioner.  I mean I guess some people dont want to use chemicals but its like literally a few ml on water than has already been chemically treated.

 

I fill up the jugs each time I do a water change. I've been doing this for almost 2 years without any issues so I see no reason to add additives.

[mynameisnobody]

@Lonkley everyone’s different, I go through a gallon of water conditioner per year. 

Edited May 6 by mynameisnobody

[lefty o]

if you give it enough time to off gas, nothing wrong with it. in other words if it aint broke, dont fix it.

[Odd Duck]

On 5/6/2024 at 4:50 PM, Herefishie said:

I fill up the jugs each time I do a water change. I've been doing this for almost 2 years without any issues so I see no reason to add additives.

You do need to leave the jugs open for the chlorine gas to escape and likely a few days would be needed if the jugs are filled to the top with a small surface area.  Or you could do a bucket with a wide surface area and use an air pump and airstone to aerate it for 24 hours and it would be ready to use.  This is always what we did “back in the day” before dechlorinators became popular and before chloramine was used.

[Herefishie]

On 5/7/2024 at 9:20 AM, Odd Duck said:

You do need to leave the jugs open for the chlorine gas to escape and likely a few days would be needed if the jugs are filled to the top with a small surface area.  Or you could do a bucket with a wide surface area and use an air pump and airstone to aerate it for 24 hours and it would be ready to use.  This is always what we did “back in the day” before dechlorinators became popular and before chloramine was used.

I never leave lids on them and I use a mixture of half-and-half tapwater and RO water. They usually sit for at least five days. Thanks for your input.

[dasaltemelosguy]

On 5/6/2024 at 12:36 PM, Herefishie said:

I wrote to my local water department asking if they periodically flush with chlorine as I have heard some cities do. I have never registered any chlorine in my tapwater. This was, in part, their response. I'm not a scientist so I'm wondering if this is a super low amount of chlorine and that's why I never have to treat my water?
"We received your inquiry. We don't use chloramines but we do chlorinate the water.  Chlorine residuals in the distribution system range from 0.3 - 1.2 mg/L.  The system isn't periodically flushed with chlorine, there is a chlorine residual in the system."

0.3-1.2 mg/l (or 0.3-1.2 PPM) is actually on the low side by municipal water supply chlorination standards. Here in Los Angeles, it's not uncommon to see 4PPM straight out of the tap.

When municipalities "shock" the system, it can be temporarily as high as 200PPM. Shocks tend to be performed with gas-only as 200PPM of chloramine would stay toxic for too long a period. I believe @Guppysnail has encountered problems with her water supplier shocking the system unknowingly. 

This crude chart below shows comparative off-gassing times of chloramine and chlorine with some variables introduced.

The introduction of an external energy source accelerates this. Heat, electricity and UV light all remove chlorine if enough time is allowed.

Very powerful UV light is used to dechlorinate without chemicals in real time. They are very powerful lights known as medium pressure UVC but notice below, even a 13-watt aquarium UV light greatly accelerated the dissociation of chlorine and even chloramine from 180 hours to 6-8 hours: 

 

[Herefishie]

On 5/7/2024 at 9:53 AM, dasaltemelosguy said:

0.3-1.2 mg/l (or 0.3-1.2 PPM) is actually on the low side by municipal water supply chlorination standards. Here in Los Angeles, it's not uncommon to see 4PPM straight out of the tap.

When municipalities "shock" the system, it can be temporarily as high as 200PPM. Shocks tend to be performed with gas-only as 200PPM of chloramine would stay toxic for too long a period. I believe @Guppysnail has encountered problems with her water supplier shocking the system unknowingly. 

This crude chart below shows comparative off-gassing times of chloramine and chlorine with some variables introduced.

The introduction of an external energy source accelerates this. Heat, electricity and UV light all remove chlorine if enough time is allowed.

Very powerful UV light is used to dechlorinate without chemicals in real time. They are very powerful lights known as medium pressure UVC but notice below, even a 13-watt aquarium UV light greatly accelerated the dissociation of chlorine and even chloramine from 180 hours to 6-8 hours: 

 

Wow. What a lot of great information. Thank you so much. They did tell me that they don't ever shock the system so fingers crossed that's the truth. I always test the water before I use it though just to be sure. Again, lots of great info. Thank you.

[Cinnebuns]

On 5/6/2024 at 2:36 PM, Herefishie said:

I wrote to my local water department asking if they periodically flush with chlorine as I have heard some cities do. I have never registered any chlorine in my tapwater. This was, in part, their response. I'm not a scientist so I'm wondering if this is a super low amount of chlorine and that's why I never have to treat my water?
"We received your inquiry. We don't use chloramines but we do chlorinate the water.  Chlorine residuals in the distribution system range from 0.3 - 1.2 mg/L.  The system isn't periodically flushed with chlorine, there is a chlorine residual in the system."

You still want to handle the chlorine they distribute. You don't have to do this by treating with dechlorinator like chlorimines but then you need to gas off. Chlorine will go away over time but putting this water directly from the tap to your tank is a risk to the beneficial bacteria. Yes, it's a low amount and it's not chloramine but I wouldn't risk it and would gas off or treat if it were me.