Ilford Rapid Fixer ammonia fumes + tap water

Hallo, I hope someone can help with my query - using freshly bought Ilford Rapid Fixer at 1:9 dilution with my tap water is very very smelly; the eye watering ammonia smell stinks on freshly mixed. Did the same mix (1:9) but using distilled water today - no smell, well a very faint "this is not pure water" smell but nowhere near as bad as with the tap water. Difference is enough to make printing viable!

Why is the ammonia being released when using the tap water?

I am in a hard water area, as far as I remember the tap water goes cloudy with sodium hydroxide, if that helps.

Thanks,
Sim2.

Sim2 said:

I am in a hard water area, as far as I remember the tap water goes cloudy with sodium hydroxide, if that helps.

Thanks,
Sim2.

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I am in a very hard water area as well in S Northants. Our drinking water hardness figures from admittedly 3 years ago apparently matches top of the league hardness and I have never noticed any eye watering ammonia smell. Has this ammonia smell always been present. I suspect that water quality( not its safety for drinking) can vary quite markedly for short periods . Few of us I suspect drink pure tap water or otherwise mix it with chemicals( other than a few home darkroom workers) that might affect its smell so the public never suspects anything.

pentaxuser

The pH of the fixer concentrate as listed in Iford's MSDS for the product is 5.1. It is difficult to imagine water that is so hard as to be able to release ammonia gas in any appreciable amount. The pH of the diluted fixer would have to be over 8.0 in order to do this. I suspect that you are either not using a stopbath or are not allowing the stop to neutralize any residual developer carried over by the prints. However ammonia is one of those chemicals whose smell is easily detected in very small amounts. If you find the smell objectionable then try another brand of rapid fixer or switch to a sodium thiosulfate based one.

I remember once mixing some Dektol and finding that it didn't "work." Just on a hunch I called the water department and found that they'd sent a slug of acid down the lines near my house, by the time it got to my tap it was "safe" to drink, but still killed my Dektol. Arrrgh! At least I hadn't made up some D-76 1 to 1.

Moral of the story? Watch that tap water! Since then I use distilled water to mix at least the developer.

Gerald C Koch said:

The pH of the fixer concentrate as listed in Iford's MSDS for the product is 5.1. It is difficult to imagine water that is so hard as to be able to release ammonia gas in any appreciable amount. The pH of the diluted fixer would have to be over 8.0 in order to do this. I suspect that you are either not using a stopbath or are not allowing the stop to neutralize any residual developer carried over by the prints. However ammonia is one of those chemicals whose smell is easily detected in very small amounts. If you find the smell objectionable then try another brand of rapid fixer or switch to a sodium thiosulfate based one.

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Ironically I have been using a "plain" sodium thiosulphate fixer however the fixing times are quite long and a sight question on getting clean paper whites - different issues I think - however, the rapid fix was a fresh mix in a mixing pot then tray; it smelt even before using with prints! Didn't improve or get any worse during printing.
When mixed with the distilled water, no or very marginal smell either on initial mixing or in use. Perhaps my nose is rather susceptible to ammonia!
May try one of the odourless fixers, once I can find out what they are made with, but using the distilled water seems the way forward for the moment.
Cheers guys.

I've seen (or smelled) the same effect - sort of "old socks in ammonia" when using tap water with Ilford rapid fix.

Doesn't happen if I use our filtered faucet, until the fix gets really old/depleted (or maybe it's contamination from the tap-waterr stop bath?)

These days my processes are a choice between distilled, filtered, or plain tap water. Distilled for film and lith developer (since the old brown is around forever), filtered for fixer, toners, etc. I buy distilled by the gallon and I have to tote filtered upstairs in pitchers, so I try to choose wisely.

Gerald C Koch said:

The pH of the fixer concentrate as listed in Iford's MSDS for the product is 5.1. It is difficult to imagine water that is so hard as to be able to release ammonia gas in any appreciable amount. The pH of the diluted fixer would have to be over 8.0 in order to do this.

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I'm not a chemist. What is the formula to determine the pH of the water required to give the resulting working strength fixer a pH of 8.0 ? Hard water can have a pH of 8.5, but obviously the mixture will have a lower pH than the hard water.

Very hard water often contains quite a bit of calcium salts (and others), and thus could shift the pH if the water is alkaline enough. Addition of Sodium Hydroxide can make it cloudy by precipitating Calcium Hydroxide. This would become more pronounced when you dilute it with the same water.

I would not drink that water!

PE

Thanks all for the replies.
Apart from guessing that the alkali level of the tap water *might* be affecting the fixer smell I did not/do not *know* the correct answer to the issue. What I do know is that one water produces fumes I find too strong, another type of water does not produce fumes I find too strong; so, for me, I will choose to use the water that doesn't produce the fumes for me when I use this type of fixer.
Apart from believing that the water is rather alkali, based on my previous experience with the tap water and sodium hydroxide going cloudy, I just wanted to check if there was another "easy" and "obvoius" answer long the lines of "yes, if you have x in your water, ammonia will be released from hard water".
In some ways you guys have confirmed my initial suspicions, for which I thank you - good to have some confirmation of my non-chemist understanding of these issues!
Sim2.

Michael R 1974 said:

I think you're misreading what Gerald is saying. He's saying the pH of the working strength fixer would have to be at least 8 to release ammonia gas, but he's not saying water can increase the working strength fixer pH to 8. It can't unless something is very wrong.

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Yep, and I'm trying to elicit exactly how wrong !! What would the pH of the contaminated water have to be ? (feel free to assign a buffering capacity to the "water" as well since I'm sure that is another variable affecting the answer)

Michael R 1974 said:

It's a complicated situation with many variables, but to make a long story short - extremely wrong.

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I totally realise the contaminated "water" would be very alkaline, and possibly generously buffered. so it was purely a hypothetical thought bubble I had. I also realise it wouldn't be potable and is therefore not the cause of the ammonia smell. Nevertheless if the equation was not too lengthy, I was curious to know what it would take from a theoretical point of view. But it sounds like it isn't a simple equation after all. Although "simple" is a relative term of course .