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Re: chlorine, chloramines and sodium thiosulphate
For those of us without the ability to run everything through a carbon block
filter, what is the best solution with the least about of chemicals?
If I use sodium thiosulphate, how can I get rid of the ammonia?
Drummond howard
Gaithersburg, MD
>From: Wright Huntley <huntley1 at home_com>
>Reply-To: killietalk at aka_org
>To: killietalk at aka_org
>Subject: Re: chlorine, chloramines and sodium thiosulphate
>Date: Tue, 03 Jul 2001 10:46:19 -0700
>
>Alberto Restrepo Ubach wrote:
>
> > ... Now, another question for those of
> > you with some knowledge of water chemistry:
> >
> > I have access to lots of sodium thiosulphate. As I understand it,
> > that is the stuff out of which most 'old style' de-chlorinators were
> > made. In other words it works great to neutralize chlorine. But now
> > that the water supply of most metropolitan areas in the U.S.A.
> > contains chloramines in significant amounts (i.e.: enough to kill my
> > killies), is sodium thiosulphate of much use? Does it act on
> > chloramines the same way it does on chlorine? Or does it have an
> > adverse consequence? (I seem to remember a discussion some time ago
> > in which someone suggested that the typical de-chlorinator was --at
> > the very least-- useless for chloramines, and maybe even harmful.)
>
>Charles Harrison and I have had many an enjoyable "discussion" about that
>here. Since he is a real chemist, and I'm not, it makes for an uphill fight
>for me every darned time. ;-)
>
>Much of that difference has been a matter of degree, and what the
>particular
>situation was. I have not always been explicit enough about the conditions
>that bothered me. [Please forgive me if I get windy about those here.
>Charles will just flay me, again, if I don't. <G>]
>
>Hypo (thiosulfate) is often fine for partial water changes on adult fish in
>well-aerated tanks. The small amount of released ammonium stays in that
>form, mostly, and doesn't convert to very much nasty ammonia in most normal
>water at any reasonable pH. So far, so good.
>
>Unfortunately, EPA has mandated, in addition to chloramine, that many older
>municipalities must add enough alkalis or base chemicals to their system to
>bring pH up to around 8 or 9 to retard etching of lead and copper from
>older
>pipes. This is mostly a problem in areas with naturally occurring soft,
>acid
>water, and depends a lot on what they use. If it truly raises alkalinity,
>it
>buffers, and makes for a problem with chloramine as we shall see.
>
>Major fishroom wipeouts with hypo and chloramine have happened in
>situations
>where 100% water changes are common, particularly in harder water areas,
>where the tap water is buffered too well to allow any pH drop. Without the
>usual nitrates, and other organics to drop the initially high pH, the burst
>of ammonia was more than enough to be lethal. Betta and killy folks who do
>100% changes on shoeboxes, jars or or small tanks were, by far, the worst
>hit.
>
>Between the "all dead the same day" incidents (I know, personally, of
>several) and the relatively harmless situation lies a nebulous continuum of
>conditions that can be aggravated by the burst of ammonia without killing
>everyone off. Symptoms can be vague and often delayed for some time.
>
>Baby fish get clubbing of the finer gill filaments and become permanently
>stunted. Adult fish are temporarily, and sometimes permanently, sterilized.
>Respiration can become labored as the gills are seared. General health can
>be reduced, making diseases more common. [Ammonia exposure is a known
>precursor of most bacterial gill diseases.] None are easy to spot, but
>these
>are all things we do *not* want to do to our fish.
>
>First, what level of ammonia is harmful? Spotte in his _Fish and
>Invertebrate Culture_ cites references showing that a wide variety of
>harmful effects result from various sub-lethal doses of ammonia. The
>amounts
>for permanent damage are truly tiny, as low as 0.006 ppm of un-ionized
>ammonia for baby fish. See pp 104-106 for a long list of references on the
>problem. These effects are shown to not be species dependent, BTW, and
>apply
>to most all teleosts about equally. [Killies are just so darned tough they
>may be slower to *show* outward symptoms than some other fish, though.]
>
>OK. One may well ask how much of the total ammonium/ammonia is in the
>damaging un-ionized ammonia form? The equililibrium between ammonium and
>ammonia changes smoothly between almost no ammonia well below pH=7 to quite
>a lot at 8 and a whole lot at 9 (if we are concerned with only 0.006ppm).
>
>For example, at those three pH levels and at 20C, the percent of the
>combination as ammonia is only 0.5% at pH=7, but rises to almost ten times
>that, 4.7%, at pH=8. It is 35.8% at pH=9 or over 70 times as much as at 7!
>
>Essentially, more available hydrogens (H+) means more NH4+ ions and less
>un-ionized NH3. Makes some sense. Since the number of available hydrogens
>drops 10X for each pH point of increase, we might expect the equilibrium to
>somewhat follow that pattern, and it does pretty much that.
>
>Since we already know that 0.006ppm of ammonia is measurably harmful, we
>want to stay well below that level. That means that the *total* measured
>ammonium/ammonia, per your test kit, must be well below 0.128ppm to be safe
>at pH=8 and 20C. Unfortunately, that level of combined ammoniums isn't even
>detectable on most test kits, but can harm your fish, anyway. Babies could
>be permanently damaged but older fish only temporarily stressed.
>
>At pH of 7, it would take a reading of 1.2ppm to reach that same ammonia
>level (0.5% of 1.2ppm= 0.006ppm). That, BTW, isn't very far from what some
>domestic-water chloramine doses release when treated with sodium
>thiosulfate.
>
>The situation gets even worse at higher temperatures as the ionization
>constant of water drops and the dissociation constant of ammonium
>increases.
>It is further made worse by poor oxygenation and other factors that can
>combine with ammonia to increase damage. The damage is sometimes
>recoverable
>in older fish, but often permanent in small babies (where we are more
>likely
>to do 100% changes, too).
>
>Depending on how anal you are about your fish husbandry, the use of hypo on
>chloramine should be pretty questionable, at best, and should be avoided,
>like the plague, for treating water for new babies.
>
> >
> > And last BUT NOT LEAST, if sodium thiosulphate is not very useful
> > given modern municipal water treatments, what chemical(s) are used in
> > products like AmQuel to 'neutralize' (is that the right term?)
> > chloramines?
>
>I'm not entirely enamored of them, either, for they are generally tanning
>(protein cross-linking) agents very similar to formaldehyde. In small
>amounts they apparently are harmless to fish, but they have other drawbacks
>for the breeder.
>
>All I have tested carefully (Prime, Amquel and Ammo Lock 2) kill small
>invertebrates like daphnia, ostracods, moina, hydra and flatworms, just
>like
>formaldehyde does. I concluded they probably also do that to a number of
>the
>soft smallest ones we depend on for baby starter foods, like paramecia,
>rotifers, etc.
>
>Interestingly, I have *not* noticed that they precipitate out the
>free-swimming flagellants from green water (presumably Euglena species).
>
>I use Amquel, generously, when shipping fish. Even when starved, a little
>ammonia builds up and the ability to sequester it is useful there to
>minimize stress. Otherwise, I use multiple carbon filters on both RO and
>tap
>water to *very-slowly* remove the chloramine from the water before it is
>stored for use. [Testing for chlorine between filters tells me when it is
>time for a change.]
>
>I can pull a tuft of Java moss from almost any of my tanks, put a drop of
>Liquifry #1 on it, and generate a cloud of infusoria in a new hatchling
>container in less than a day. When I used to use Amquel in all my tanks,
>that was a much more iffy proposition, I think. It is always possible that
>absence of dechloraminators makes my fishroom more sensitive to swimming
>parasites like Ich or Velvet, but I have not observed that to be true.
>Healthy fish are pretty good at resisting them, though, anyway.
>
>Sorry Charles, but I guess my fishkeeping motto is slowly becoming "Better
>things for better living *without* chemistry!" <VBG>
>
>Wright
>
>--
>Wright Huntley, Fremont CA, USA, 510 494-8679 huntley1 at home_com
>
>"Let us, for a moment, take the sex-education pushers at their word:
>If you teach a child how to use a condom, you're promoting safety -- not
>usage.
>...Why, then, doesn't the same logic apply to guns?"
> --Michelle Malkin
>
> http://environmental.networkroom.com/
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