Using fish tank chlorine remover as fixer

koraks · Jul 31, 2022

Don Heisz said:
There would be one way to find out... It might sepia tone while it fixes.... Or just wreck the image.

It will indeed sepia tone, and in fact it will sepia tone the undeveloped silver even faster than the already developed silver. So yeah, it would wreck the film instantly.

pentaxuser said:
What I might be prepared to pay a small premium for would be a highly concentrated rapid fixer in liquid form such that, say, 500ml was the equivalent of 5L but I fear that concentrated liquid chlorine remover can be a small amount for 10s if not 100s of gallons of fish tank water but would not be small for the amounts required for film and paper

Well, chlorine remover is virtually always sodium thiosulfate, so not a rapid fixer. I've said it before, but if you're serious about this, see if you can find any ATS fertilizer that contains only ammonium thiosulfate. It's out there on the market, sources will depend on the country, and you might have to buy in bulk. Alternatively you could simply look for solid ammonium thiosulfate. I bought it a couple of times and contrary to what people often say, it keeps quite well in a sealed container.

Tim Stapp · Sep 23, 2022

One of my customers is a pool chemical manufacturer. Every year, they get in container loads of chemicals, not to mention rail tank cars of chemicals.

While there, I saw 50 lb. bags of marked Sodium Thiosulfite-Photographic Grade. So indeed, look at the pool supply centers for what you might need.

No, sadly: they would/could not sell to me.

Donald Qualls · Sep 26, 2022

I see it on Amazon for as little as $70 for 25 lb bucket, free next day shipping for Prime members (one guess where I'll buy mine next time I need a bucket). Smaller packages are, of course, more per pound -- as are some of the larger ones, so you do need to pay attention.

pentaxuser · Sep 26, 2022

Unless we enjoy saying more on this topic we may be wasting out time as the OP hasn't been seen since the day he posted this thread

pentaxuser

alanrockwood · Dec 6, 2022

Maybe a dumb idea, but what if one were to start with sodium thiosulfate.

Then add an NH3 in the form of household ammonia in quantity so that the number of NH3 molecules is equal to the number of sodium ions.

Next add enough hydrochloric acid to neutralize the NH3, thus creating a solution of ammonium thiosulfate plus sodium chloride.

It seems to me that this would create a rapid fixer which I believe is an ammonium thiosulfate solution, with sodium chloride present as spectator ions. The NaCl in the solution probably won't do much, other than changing the ionic strength. However, the ionic strength of the solution will be dominate largely by the thiosulphate ions because they are doubly charged, so I don't expect the sodium chloride to play a very important part in any chemistry that would take place subsequently.

All of the chemicals mentioned above are readily available. The hydrochloric acid is available under the name "muriatic acid."

Any thoughts on this scheme?

alanrockwood · Dec 7, 2022

pentaxuser said:
Unless we enjoy saying more on this topic we may be wasting out time as the OP hasn't been seen since the day he posted this thread

pentaxuser

It seems to me that discussions like this have a larger role than just giving information to the person who originally posted. They also serve to exchange information with other people who would read the thread.

koraks · Dec 7, 2022

pentaxuser said:
Unless we enjoy saying more on this topic

Which seems to be the case, and as @alanrockwood points out, the use of threads like these stretch far beyond the original topic starter. I think many of us share the experience of searching for a bit of knowledge, stumbling on some Photrio threads and finding interesting stuff there.

Besides, nobody can force someone to keep reading, so there's very little use in making the same observation time and again. Sure, it's nice if someone sticks around to say 'thank you' or post some follow-up questions, but nobody's obliged to do anything.

@alanrockwood as to your idea of making an in-situ rapid fixer: yes, but I'm no chemist, so take this the right way, but is there no risk of inadvertently releasing chlorine gas this way?

alanrockwood · Dec 7, 2022

koraks said:
Which seems to be the case, and as @alanrockwood points out, the use of threads like these stretch far beyond the original topic starter. I think many of us share the experience of searching for a bit of knowledge, stumbling on some Photrio threads and finding interesting stuff there.

Besides, nobody can force someone to keep reading, so there's very little use in making the same observation time and again. Sure, it's nice if someone sticks around to say 'thank you' or post some follow-up questions, but nobody's obliged to do anything.

@alanrockwood as to your idea of making an in-situ rapid fixer: yes, but I'm no chemist, so take this the right way, but is there no risk of inadvertently releasing chlorine gas this way?

To release chlorine would require oxidation of the chloride ions, and there is no oxidizer among the chemicals, so I don't think there is a risk of chlorine gas generation.

pentaxuser · Dec 7, 2022

I thought I qualified my statement to make it clear that my only concern was to point out that the originator of the thread who was asking about something specific had not returned. However I do agree that in most cases this doesn't seem to matter so I'll refrain from mentioning this again

pentaxuser

koraks · Dec 7, 2022

alanrockwood said:
To release chlorine would require oxidation of the chloride ions, and there is no oxidizer among the chemicals, so I don't think there is a risk of chlorine gas generation.

I thought so, but I also thought it was a good idea to make this explicit. Thanks.

@pentaxuser no worries; I hope you recognize that all this is not in vain

Donald Qualls · Dec 7, 2022

alanrockwood said:
what if one were to start with sodium thiosulfate.

Then add an NH3 in the form of household ammonia in quantity so that the number of NH3 molecules is equal to the number of sodium ions.

Next add enough hydrochloric acid to neutralize the NH3, thus creating a solution of ammonium thiosulfate plus sodium chloride.

I don't see any advantage to this over the relatively common method of adding ammonium chloride to the sodium thiosulfate solution. Doing so produces a "semi-rapid" fixer, nearly as fast working as ammonium thiosulfate formula, but with capacity intermediate between hypo fixers and rapid fixers.

koraks · Dec 7, 2022

Donald Qualls said:
I don't see any advantage to this over the relatively common method of adding ammonium chloride to the sodium thiosulfate solution.

I do, although it's a small benefit: ammonia and hydrochloric acid = supermarket chemistry. Ammonium chloride I actually have to order online

ags2mikon · Dec 7, 2022

If you live in a corn growing area ATS 12-0-0-26s is all around you in ag supply stores. I think 2.5 gallon is the smallest size sold. I have been using agfa 304 type semi rapid fixer and when done I pour it through fine steel wool to remove the silver and pour it on the trees. It has about half the life of the real rapid fixers but it does not matter. It gets re-used.

Donald Qualls · Dec 7, 2022

koraks said:
I do, although it's a small benefit: ammonia and hydrochloric acid = supermarket chemistry. Ammonium chloride I actually have to order online

I used to see ammonium chloride sold as sal ammoniac in pharmacies (though you wouldn't want to pay pharmacy prices). In Europe (especially Netherlands) it's used as "salmiak" for "salty" candy.

The positive advantage of using ammonium chloride here vs. ammonium hydroxide and hydrochloric acid is you don't have to deal with the smell of the ammonia or the hazardous acid handling.

koraks · Dec 7, 2022

Donald Qualls said:
In Europe (especially Netherlands) it's used as "salmiak" for "salty" candy.

Ah yes, of course. It's not very popular anymore though, and never sold in a pure form for food/candy 'applications'. There's always colorants and additional flavorings added, not to mention a truck load of sugar probably.

Pharmacies also work differently from what you may expect around here, but let's not go into the national intricacies of retail and drug distribution. Interesting stuff, but rest assured that buying pure ammonium chloride in at least The Netherlands relegates one to (mostly) online outlets that retail common chemistry.

I agree on the smell & acid handling disadvantages.

alanrockwood · Dec 7, 2022

Donald Qualls said:
I don't see any advantage to this over the relatively common method of adding ammonium chloride to the sodium thiosulfate solution. Doing so produces a "semi-rapid" fixer, nearly as fast working as ammonium thiosulfate formula, but with capacity intermediate between hypo fixers and rapid fixers.

Adding ammonium chloride to sodium thiosulfate is chemically equivalent to the scheme I suggested.

A possible advantage is that the scheme I proposed relies entirely on easily obtained chemicals. I don't know if ammonium chloride is easily obtained or not, but if not then the scheme I suggested could be easier to implement. (This point was already noted by Don Quails.)

Question: What causes the ammonium chloride/sodium thiosulfate mixture to have a lower capacity than pure ammonium thiosulfate?

Donald Qualls · Dec 7, 2022

alanrockwood said:
What causes the ammonium chloride/sodium thiosulfate mixture to have a lower capacity than pure ammonium thiosulfate?

I don't know for certain, but it most likely has to do with the leftover sodium or chloride ions in the solution. One or another of those probably winds with dissolved silver ions in a way that ties up thiosulfate more than would be the case in a straight ammonium thiosulfate fixer. Adding sodium thiocyanate might help here (both in fixing speed and capacity), but that's very definitely not a supermarket chemical.

pentaxuser · Dec 7, 2022

koraks said:
I do, although it's a small benefit: ammonia and hydrochloric acid = supermarket chemistry. Ammonium chloride I actually have to order online

So hydrochloric acid can be purchased from a supermarket?. What form does this take in a supermarket?

thanks

pentaxuser

Donald Qualls · Dec 7, 2022

pentaxuser said:
So hydrochloric acid can be purchased from a supermarket?. What form does this take in a supermarket?

thanks

pentaxuser

Maybe not supermarket -- maybe Big Box store. Janitor in a Drum was weak HCl, but at home improvement stores it's sold as "muriatic acid" for cleaning concrete. Not sure what strength, however, which is somewhat critical in this case (might be sufficient to manage the solution pH if you have a pH meter).

koraks · Dec 7, 2022

pentaxuser said:
So hydrochloric acid can be purchased from a supermarket?. What form does this take in a supermarket?

Around here, yes, in the supermarket if you're lucky. And definitely in drugstores, DIY stores etc.
What form...well, obviously an aqueous solution, as usual. I wouldn't want to live near a shop that retails it in pure gas form - too much noise from the sirens!
10% concentration is usual here, intended for cleaning purposes.

gone · Dec 7, 2022

I'm a big fan of DIY photography, but on this, one might not know if something is adequately fixed until many, many years later. At least I don't know of a way to test to see if it has gotten properly fixed. Other than seeing if the print turns brown, or not.

Anon Ymous · Dec 7, 2022

momus said:
I'm a big fan of DIY photography, but on this, one might not know if something is adequately fixed until many, many years later. At least I don't know of a way to test to see if it has gotten properly fixed. Other than seeing if the print turns brown, or not.

There are ways to figure out if your print/film is adequately fixed and this involves sodium sulfide, or selenium toner. Search for Kodak ST-1 test solution.

faberryman · Dec 7, 2022

koraks said:
Around here, yes, in the supermarket if you're lucky. And definitely in drugstores, DIY stores etc.
What form...well, obviously an aqueous solution, as usual. I wouldn't want to live near a shop that retails it in pure gas form - too much noise from the sirens!
10% concentration is usual here, intended for cleaning purposes.

I have not seen hydrochloric acid in grocery stores around where I live. However, it is sold in a less pure form as muriatic acid in Home Depot and Lowe's. If you want the real thing, you need to order it from a chemical supply house or, unsurprisingly, Amazon.

Is there any reason people are looking for alternate sources of fixer? Something other than cost savings? It seems like it would take a while to work through a 50 pound bag of sodium thiosulfate. I guess if you develop a lot of film and make a lot of prints it might make sense.

fgorga · Dec 7, 2022

Donald Qualls said:
Maybe not supermarket -- maybe Big Box store. Janitor in a Drum was weak HCl, but at home improvement stores it's sold as "muriatic acid" for cleaning concrete. Not sure what strength, however, which is somewhat critical in this case (might be sufficient to manage the solution pH if you have a pH meter).

Muriatic acid, as it is commonly sold (in the US, don't know about other regions) is roughly 32% HCl (about 12 molar) the same as lab grade concentrated HCl. The actual concentration should be listed on the container.

pentaxuser · Dec 7, 2022

Well I certainly have never seen it in U.K. supermarkets but no matter. The problem for all here who are not chemists is that largely what I think faberryman hints at. There is a lot to learn before feeling confident about even trying to make what may or may not match commercial fixer and the time and effort needed may not be matched by the benefits

However it might be argued that we have a conversation between "specialists" which is quite legitimate

pentaxuser

Using fish tank chlorine remover as fixer

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