How long does it take for dechlor to kill chlorine ?

  • We are currently upgrading MFK. thanks! -neo
12 Volt Man;3450526; said:
no.

one thing to remember that is worth posting in this thread is that chlorine does not kill bacteria on contact. it takes time to work, as in minutes to work.

which is lots of time for your dechlor to mix with the new water before any harm is done. now, this does depend on its concentration of course. but the levels found in normal tapwater will not kill your nitrifying bacteria instantly.

In my line of work, I have had to take courses in chlorine disinfection (I am a wastewate treatment plant operator). we don't use chlorine to disinfect wastewater anymore (we use UV light) but I still took training courses because we are responsible for knowing about it for our certification exams.

okay, some info that might be useful for this thread: (this is all from my head, so bare with me lol)

chlorine is a surface disinfectant. it only works when the products of chlorine and water (hydrochloric acid (HCL) and hypochlorous acid (HOCL) come into direct contact with the surface of a bacterium.

the HCL is higly reactive and does not last long as it quickly reacts with other organics in the water, so the main disinfectant in tap water is the hypochlorous acid.

now, we hear a lot of talk about chloramines (formed from the reaction of ammonia and chlorine when ammonia is added at the water plant).

this is actually not a very good disinfectant compared to the hypochlorous.

but here is why it is important: it doesn't break down easily so it remains available to disinfect as the water from the treatment plant flows through the distribution system of pipes to get to the end of your tap.

what this means is that any biofilms present in the piping will not be able to contaminate your water and make you sick.

I have too have been using AquaPlus from nutrafin for almost 20 years. I always add it to the tank prior to the addition of the new water.

so, you have:

old water (with no chlorine) + dechlor

add tap water

as it is added it reacts with the dechlor and is made safe before any harm is done to your fish or bacteria..


I sure love it when people offer me education via facts as opposed to random guidance via speculation...

Thanks 12V!!!
 
I mentioned contact time in my post about chlorine. I know in ontario, the standard contact time for water at the treatment plant to be exposed to chlorine is 20 minutes. granted, no doubt they are extra conservative.

for wastewater (my side) it used to be 12-15 minutes if I recall. the creek is not as particular about the level of faecal coliform bacteria in the water as humans are when they drink it :)

the water operators have whats called a multiple barrier concept set up.

remember how I said that chlorine is a surface disinfectant? well, if you have a bug hidden inside a dirt particle, the chlorine cannot get to it.

this is why tap water must be very clear (low suspended solids) because suspended solids can trap bugs and sheild them from the chlorine. the way around this is filtration prior to disinfection, hence the multiple barrier concept.

a bit off topic I know, but if we are talking about chlorine in tap water, I think it helps to have some background info as to how it is used at the treatment plant.

(when I was studying to become an operator, I didn't know where I would end up, so I got certified in both water and wastewater, but ended up in wastewater as the job offer came up first and I was poor LOL)
 
Hey quick question folks. I found the average chlorine level is .24 in my area. That is all it says .24 just chlorine no chloramine.... It gives no ppm or whatever reading simply states .24 is that high or low ?
Heres a link to the article about my water... This also proves my paranoia about the nitrates in our tap water..
http://www.cityofwinters.org/pdf/CCR 2008 - final.pdf


Check out page 2
 
Thanks 12 volt man. Is that a lot or a little chlorine?
 
12 Volt Man;3450526; said:
no.

one thing to remember that is worth posting in this thread is that chlorine does not kill bacteria on contact. it takes time to work, as in minutes to work.

which is lots of time for your dechlor to mix with the new water before any harm is done. now, this does depend on its concentration of course. but the levels found in normal tapwater will not kill your nitrifying bacteria instantly.

In my line of work, I have had to take courses in chlorine disinfection (I am a wastewate treatment plant operator). we don't use chlorine to disinfect wastewater anymore (we use UV light) but I still took training courses because we are responsible for knowing about it for our certification exams.

okay, some info that might be useful for this thread: (this is all from my head, so bare with me lol)

chlorine is a surface disinfectant. it only works when the products of chlorine and water (hydrochloric acid (HCL) and hypochlorous acid (HOCL) come into direct contact with the surface of a bacterium.

the HCL is higly reactive and does not last long as it quickly reacts with other organics in the water, so the main disinfectant in tap water is the hypochlorous acid.

now, we hear a lot of talk about chloramines (formed from the reaction of ammonia and chlorine when ammonia is added at the water plant).

this is actually not a very good disinfectant compared to the hypochlorous.

but here is why it is important: it doesn't break down easily so it remains available to disinfect as the water from the treatment plant flows through the distribution system of pipes to get to the end of your tap.

what this means is that any biofilms present in the piping will not be able to contaminate your water and make you sick.

I have too have been using AquaPlus from nutrafin for almost 20 years. I always add it to the tank prior to the addition of the new water.

so, you have:

old water (with no chlorine) + dechlor

add tap water

as it is added it reacts with the dechlor and is made safe before any harm is done to your fish or bacteria..
Bravo!! this should be a point to quote in the never ending battle of to chlorinate in the tank or not...
Thank You again for the Ammo...;)
 
tcarswell;3451080; said:
Thanks 12 volt man. Is that a lot or a little chlorine?




12V is correct that 1 mg/L is approx 1 ppm (this is not an exact translation and the larger the numberical value the more off the translation is)...

If 12V is correct that ".24" means .24 mg/L... Then .24 ppm of chlorine is not high at all... At the recommended dosage of Prime, it is supposed to treat up to 3.3 mg/L of chlorine.

Quoted from the Directions on the product description of Prime on Seachem's website:

Use 1 capful (5 mL) for each 200 L (50 gallons*) of new water. This removes approximately 0.8 mg/L ammonia, 1.2 mg/L chloramine, or 3.3 mg/L chlorine.

Do note the use of the word "or".
 
Nice thanks!
 
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