Switch to English Language Passer en langue française Omschakelen naar Nederlandse Taal Wechseln Sie zu deutschen Sprache Passa alla lingua italiana
Members: 70,295   Posts: 1,535,608   Online: 1124
      
Page 2 of 2 FirstFirst 12
Results 11 to 12 of 12
  1. #11
    Matthew Gorringe's Avatar
    Join Date
    Apr 2006
    Location
    Sydney, Australia
    Shooter
    Medium Format
    Posts
    461
    Images
    25
    Quote Originally Posted by Matthew Gorringe View Post
    Is pharmaceutical grade citric acid likely to need buffering and where do the sodium salts come from, tap water?
    Sometimes I'm stupid, the developer obviously.
    Matt Gorringe

  2. #12
    Photo Engineer's Avatar
    Join Date
    Apr 2005
    Location
    Rochester, NY
    Shooter
    Multi Format
    Posts
    22,972
    Images
    65
    Quote Originally Posted by Steve Goldstein View Post
    Is there any practical value to buffering? Perhaps it increases the capacity? SB-8 exhausts rather quickly IIRC.

    The SB-8 formula is 15 grams of Citric Acid and water to make 1 liter. How much sodium carbonate (which I've got) would you suggest as a buffering agent? I don't own a pH meter.

    Thank you.
    Buffering increases capacity, but citric acid is inexpensive and you can replace the bath easily.

    The 15 g/l is used because more might be too acidic and less would be less acidic and have less capacity. As noted, carryover of sodium salts from the developer would tend to raise pH and buffer the stop, so replenishment with more fresh stop would be quite effective for a while.

    Without a pH meter or pH paper strips, I would not suggest experimentation. Just use the recommended formula.

    PE

Page 2 of 2 FirstFirst 12


 

APUG PARTNERS EQUALLY FUNDING OUR COMMUNITY:



Contact Us  |  Support Us!  |  Advertise  |  Site Terms  |  Archive  —   Search  |  Mobile Device Access  |  RSS  |  Facebook  |  Linkedin