What about Calgon?

Discussion in 'B&W: Film, Paper, Chemistry' started by Anscojohn, Jan 10, 2009.

  1. Anscojohn

    Anscojohn Subscriber

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    The thread about Arm and Hammer Washing Soda caused me to ask the experts. Can super market Calgon be used in hard water, or is some kind of special chemical needed? Thanks in advance.
     
  2. Photo Engineer

    Photo Engineer Subscriber

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    Calgon changed their formula about 20+ years ago. It is no longer suitable for use in photographic solutions as a sequestering agent. Kodak uses a product called Quadrofos. I've used EDTA and the Dequest series of chemicals with great success.

    PE
     
  3. jim appleyard

    jim appleyard Member

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  4. Photo Engineer

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    Disodium EDTA is probably best to use.

    PE
     
  5. Anscojohn

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    Thanks, fellas.
     
  6. Keith Tapscott.

    Keith Tapscott. Member

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    The stuff I use is sodium hexametaphosphate, although you could also try sodium tripolyphosphate.