Javascript Disabled Detected

You currently have javascript disabled. Several functions may not work. Please re-enable javascript to access full functionality.

Chlorine - does it really evaporate?

Started by Guest_Jeff_* , Dec 02 2009 04:32 PM

Next

Please log in to reply

23 replies to this topic

#1 Guest_Jeff_*

Guests

Posted 02 December 2009 - 04:32 PM

What I've been doing with my city water is putting it into containers and letting it sit for a week before dumping it into the aquarium. The containers I use are empty plastic milk cartons. I don't fill them up all the way to leave more surface area for the chlorine to evaporate (if that's even happening). I wait a week just in case the 24 hours deal isn't true.

So am I wasting my time? Does it only take 24 hours? Or does it work at all? Or is the carbon in the filters removing it before the fish die? What else might I not be thinking of?

To be honest I never really gave this a whole lot of thought or tried to verify its effectiveness although I've been doing it for years. Seems to have worked out fine, but wanted to hear the reality of it all from the group. Any and all details are appreciated. Thanks in advance.

Edited by Jeff, 02 December 2009 - 04:33 PM.

Back to top

#2 Guest_Jan_*

Guests

Posted 02 December 2009 - 04:55 PM

Well, I don't know if this is a "ringing endorsement" of that method, but that is what I've done for years. Recently I've been adding one of the chlorine removal products as well for good measure. But I don't trust it enough to put the water directly in the tank after treatment.

Anyone else (veteran fish keepers) with a thought on this?

- Jan

Back to top

#3 Guest_Amazon_*

Guests

Posted 02 December 2009 - 05:06 PM

It is true, after 24 hours 90% of it is gone but probably 100% of it will evaporate after 48 hours.

Back to top

#4 Guest_nativeplanter_*

Guests

Posted 02 December 2009 - 05:43 PM

It depends on whether you have chlorine or chloramine in your system. Chloramine, which has become quite popular, is more stable and lasts longer. But I don't know how long. I would not trust the "sitting out" method if you have chloramines, especially since even after it breaks down you have ammonia to deal with.

Back to top

#5 Guest_Amazon_*

Guests

Posted 02 December 2009 - 07:42 PM

Very true I forgot about chloramine. I personally just use Prime. It removes chlorine, chloramine, and ammonia. I usually just add it in the tank after the water is in without problems, but its really not the best idea.

Back to top

#6 Guest_fundulus_*

Guests

Posted 02 December 2009 - 10:02 PM

The whole point of using chloramines is that it stabilizes the chlorine and keeps it in solution longer. If a municipal system is still using chlorine, that will diffuse from solution in a day or two when exposed to the atmosphere. Local water boards are usually very happy to talk about what treatments they do, how many people are in the slightest curious about it? (Not counting old-school John Birchers worried about fluoridation...)

Back to top

#7 Guest_Sombunya_*

Guests

Posted 03 December 2009 - 12:16 AM

I am a water treatment operator, making raw water safe to drink. The comments about free chlorine and chloramines are pretty much correct. The thing about chloramines (1 part ammonia, 5 parts chlorine by weight) is that when the chlorine does go away you are left with ammonia in the water. not in any harmful quantity for humans but bad for fish. I'm not a chemist but I think PRIME de-toxifies the ammonia, converting it from NH3 to NH4.

My water service uses free chlorine as a disinfectant. I left a 5 gallon bucket out in the sun and in 8 hours virtually all of the chlorine was gone. I then left a bucket inside my home and it took about two days for it to disappear. If you need to closely match the temperature of your tank with your change water then that is the way to do it. I checked the chlorine residual using a unit made by HACH.

I use a 55 gallon drum and a small submersible pump to do water changes on my two big tanks and treat with PRIME. As 5 ml treats 50 gallons it is very economical to use.

I am an ex-John Bircher (they terminated my membership) and I am also against fluoridation of municipal water, but probably not for the same reasons other John Birchers are. We operate quite a few Fluoridation plants.

Back to top

#8 Guest_Jeff_*

Guests

Posted 03 December 2009 - 02:08 PM

Thanks very much for these replies. I had never heard of chloramines so interesting stuff here.

I have been searching the internet and have found many sites with answers. But two different answers came up so far. One or two said "days" and several more said "weeks" but none have said How Many days or weeks.

Anybody here know?

Oh, also good to finally know for sure about chlorine. Thanks for that answer as well.

Back to top

#9 Guest_gzeiger_*

Guests

Posted 03 December 2009 - 05:09 PM

I really recommend Prime by Seachem, as mentioned above. It's quick-acting enough you can actually add a dose to the remaining tank water after partially draining it and then refill the tank directly with tap water without ill effect. I've gone so far as to drain a 75 gallon down to one inch of water in the bottom (that part wasn't really intentional) and refilled with the garden hose and the fish were all fine. It costs me about $6 a month to buy enough to treat water to keep up on water changes for 270 gallons worth of tanks. It's good stuff.

I do really recommend you treat the water in buckets so fish are never directly exposed to chlorine, but many people do it my way, filling and treating at the same time. Sticking a hose in the tank makes changing water so much more convenient.

Back to top

#10 Guest_Jeff_*

Guests

Posted 07 December 2009 - 12:40 PM

OK, Prime sounds like good stuff; thanks for that.

In the meantime, it finally dawned on me to ask a woman who has lived here (in the Dallas area) her whole life and who has a son who is a "chemist" (don't remember the name of his degree). She asked him and he said in this area the chemical of choice is.....

Perchlorate

So same question for that. Anyone know how long it would take for that to evaporate (or I guess it's called dissipate)? Any info is appreciated. It's more than just practical advice I'm looking for....it's also curiousity (like the chorine question) as to how long it would take for it to happen "naturally".

Thanks to all.

Back to top

#11 Guest_AussiePeter_*

Guests

Posted 08 December 2009 - 12:36 PM

And if you want to save money you can buy sodium thiosulphate, add ~110 grams to 200 mls total, add one drop per gallon for chlorine, or two drops for chloramines. That is the active ingredient in dechlorinators. You can buy it from photographic stores as it is used in photo processing (from what I understand). I get it from my university chem stores. It costs about $15 for around 500 grams which will last you a very very long time.

Cheers
Peter

Edited by AussiePeter, 08 December 2009 - 12:36 PM.

Back to top

#12 Guest_nativeplanter_*

Guests

Posted 08 December 2009 - 12:49 PM

In the meantime, it finally dawned on me to ask a woman who has lived here (in the Dallas area) her whole life and who has a son who is a "chemist" (don't remember the name of his degree). She asked him and he said in this area the chemical of choice is.....

Perchlorate

I think your neighbor may not be quite correct. My understanding is that perchlorate is a by-product of disinfection with sodium hypochlorite. Perchlorate is actually considered to be a contaminant in drinking water. I'm sure one of our water-treatment experts can explain this more and/or correct me if I'm wrong.

The easy way to figure this out is to call your water authority and ask them what chemical they use for disinfection.

Back to top

#13 Guest_Jeff_*

Guests

Posted 08 December 2009 - 01:51 PM

Wow, this is getting more and more interesting.

OK, I will contact the local water people and see what they say. And I'll see if my friend will run it by her son again. Sometimes second-hand info can be a long way from what was said, and she was going by a voice mail and wasn't sure if it was spelled correctly and so on, so I may well have typed the wrong thing.

Thanks for all this info and I'll post again when I have more/better info on it.

Back to top

#14 Guest_BLChristie_*

Guests

Posted 09 December 2009 - 06:42 PM

I see you're in Dallas- here's a link to our local water quality reports:

http://www.dallascit...ty_reports.html

I know that Dallas uses both chlorine and chloramines as their disinfectants, and they vary quite a bit by season (up to tenfold differences - e.g. when there is a lot of rain the Ray Hubbard Reservoir and the Trinity R. have higher turbidity and we tend to see more chloramine in the municipal water). The amount of chlorine in your water can also vary depending on your proximity to the source or a pumping station. I would recommend getting yourself a $5 OTO test kit from a pool store and use that to confirm you have let all the free chlorine evaporate.

I used to process water this way (relying on the evaporation of free chlorine) for my home tanks - you take a bucket of municipal water, add a massive dose of household bleach (about 20-50 ml per 5 gal) which will break the bond between the amine group and the chlorine so that you now have free chlorine (a whole lot of it) and ammonia - when aerated for 48-72 hrs even massive quantities of free chlorine will be reduced to zero and a small airlift powered home-made zeolite filter will take care of the ammonia - I originally got the method out of an old aquarium book as a method to make up saltwater- but it worked for me quite well for years for FW make-up as well, for what it's worth.

Back to top

#15 Guest_Jeff_*

Guests

Posted 10 December 2009 - 02:58 PM

Thanks once again for the informative posts. I'm in way over my head on all of this, but the most recent reply inspired me to see if I could find a clue online, and I found a link for the small town where I live. (Waxahachie)

http://www.waxahachi...08yearfinal.pdf

About 3/4 of the way down the PDF, under the heading "Maximum Residual Disinfectant Level" it lists these 3 things:

Chloramines
Chlorite
Chlorine Dioxide

Back to top

#16 Guest_NateTessler13_*

Guests

Posted 10 December 2009 - 03:08 PM

And if you want to save money you can buy sodium thiosulphate, add ~110 grams to 200 mls total, add one drop per gallon for chlorine, or two drops for chloramines. That is the active ingredient in dechlorinators. You can buy it from photographic stores as it is used in photo processing (from what I understand). I get it from my university chem stores. It costs about $15 for around 500 grams which will last you a very very long time.

Cheers
Peter

I use Sodium Thiosulphate on my large systems at Bass Pro Shops. I can do 1000 gallon water changes and eliminate chlorine with 30 mL of a solution made of Sodium Thiosulphate and distilled water. A bucket with a gallon of distilled water and "x" amount of sodium thiosulfate (I can't recall the amount off-hand) will last me through a hundred thousand gallons of water changes or more.

Back to top

#17 Guest_Sombunya_*

Guests

Posted 11 December 2009 - 11:25 PM

I use Sodium Thiosulphate on my large systems at Bass Pro Shops. I can do 1000 gallon water changes and eliminate chlorine with 30 mL of a solution made of Sodium Thiosulphate and distilled water. A bucket with a gallon of distilled water and "x" amount of sodium thiosulfate (I can't recall the amount off-hand) will last me through a hundred thousand gallons of water changes or more.

That's a big water change!

The label on PRIME says 5 ml (about one cap full) can remove up to 3 parts per million free chlorine as well as detoxifying ammonia, nitrates etc.

I add one cap full to a 50 gallon barrel, a tiny amount I think, and I cannot measure a trace of chlorine with a good quality HACH unit.

I do 50%-60% water changes once every two weeks.

Edited by Sombunya, 11 December 2009 - 11:26 PM.

Back to top

#18 Guest_FirstChAoS_*

Guests

Posted 12 December 2009 - 01:56 AM

In what form does chlorine evaporate in? I am picturing a nightmarish scenario of poisonous clouds of green gas rising from the water and I know that is not the case. Also cholramine breaks up into chlorine and ammonia? isn't that a bad and potentially deadly combo? I know you shouldn't mix chlorine and ammonia based cleaners because toxic chlorine gas results.

Back to top

#19 Guest_BLChristie_*

Guests

Posted 14 December 2009 - 10:56 AM

In what form does chlorine evaporate in? I am picturing a nightmarish scenario of poisonous clouds of green gas rising from the water and I know that is not the case. Also cholramine breaks up into chlorine and ammonia? isn't that a bad and potentially deadly combo? I know you shouldn't mix chlorine and ammonia based cleaners because toxic chlorine gas results.

Chlorine and ammonia are both cations in solution with a 1- charge, so they don't react...what you are thinking of is the reaction of bleach (Sodium hypochlorite: NaOCl) and household ammonia (aqueous ammonium hydroxide: NH4OH) with chlorine gas produced as a by-product. Chloramine is simply chlorine bonded to an amine group (NH2) ...it is much more stable in solution than free chlorine and won't evaporate the way free chlorine (Cl-) will...

Free chlorine is what evaporates (Cl-), but chloramine does not, unless you break the amine bond by heating it or adding a large amount of either of its constituent ions (in this case more Cl-) to skew the equilibrium. When the bond is broken you are left with a larger amount of free chlorine than when you started, and the NH2 goes into equilibrium as the form we as aquarists are more familiar with transitioning between NH4 and NH3...depending on the pH and temp (solutional chemistry gets really complex really quick)

Edited by BLChristie, 14 December 2009 - 11:02 AM.

Back to top

#20 Guest_RD911_*

Guests

Posted 18 January 2010 - 03:46 AM

I use a 55 gallon drum and a small submersible pump to do water changes on my two big tanks and treat with PRIME. As 5 ml treats 50 gallons it is very economical to use.

Depending on what your local chlorine/chloramine amounts are in your tap water, 5ml of Prime could potentially treat a LOT more than 50 gallons. As an example, our local tap water contains 2 mg/l of chloramine, which means 5ml of Prime treats 100 gallons. (5ml treats 50 gallons @ 4mg/l)

Sodium thiosulfate is the only way to fly if you only have chlorine, or if you perform smaller water changes with chlormaine treated tap water. (your bio filters will remove the NH3 fairly quickly)

But for large water changes, and chloramine treated tap water Seachem Safe is the only way to go.
It's basically the dry powder version of Prime, but is FAR more economical. A 4KG container treats 400,000 gallons of my tap water, vs. 80,000 gallons from a 1 gallon jug of Prime.