FOMA Foma Citro stop bath

[PetPhoto]

on the 13th I made a 1 liter batch of it. The generic orange drink smell and tang was nice. The stop bath had no change to it after the first useage to stop 2 rolls of film in my paterson tank.

i then did a single roll in my paterson, and when pouring the stop out, it had a vinegar smell very similar to what the factory new and unopened bottle of ilford rapid fixeri opened that day.

2 days later i went to have a sniff of the fomacitro working solution,,, and it smelled like a tin can full of urine had been sitting on a side table for 4 or 5 days.

I saw the place i purchased it from said the mixed solution would last for a month, but the foma website pdf says "1 month in a fridge". SO my question is,

was that vinegary smell on the second use of the stop bath, on the day it was opened and diluted to working solution.. a sign the product was already going bad?

I develop the film in the tank, then dump out developer, pour the stop bath in, pour stop bath out, then fix, then rinse the film in the tank before taking it out of the paterson tank.

I have used the eco pro stop bath before, and that stuff in working solution lasted an easy 3 month shoved in the corner of my dark room, without fridge.

 

[Freakscene]

Test the pH. If it is still acidic, it should still be good. That’s all acid stop bath is. Acid. Well, with some indicator usually too.

 

[titrisol]

For film stop bath is not a need-to-have
You'd do much better with 2 water rinses with agitation before fixing

 

[Muggins]

The change in smell is weird. I'd not be surprised by a vinegar smell as dilute ethanoic acid would make a good stop bath - as Freakscene says, it just needs to be acidic but ammonia is a different matter. But if you are not sure test the pH - you can buy pH test paper online quite easily. If it's neutral or alkaline I'd contact the supplier and find out what they make of it.

Is it the same colour as when you made it up? It usually contains an indicator to tell you when it's no longer acid. But titrisol is right - it's not essential, just add a coupe more rinses to dilute the residual developer before you add fix.

 

[PetPhoto]

its slightly DARKER now.. i got that SMELL when i was pouring the stop bath off of the second paterson tank usage. and second usage for the stop bath.

I know there was no crossover with the fix, that would have been completely washed out by that point.

 

[Muggins]

Assuming it contains a pH indicator, overall colour will be more important than shade - which colour depends on the indicator, think litmus.