Formula and time for pure hypo fixer

<p>How many grams of pure hypo in 1 litre of water to make one shot pure hypo fixer (ie, without sodium sulfite),<br>

and what is the fixing time for Agfa APX25 film ?</p>

<p> </p>

<p>Try 180 gm of hypo made up to 1 litre with water. Test the clearing time with a bit of film and then fix for twice that time.</p>

<p>You can go for the old Agfa/OrWo A-300 formulae. A non-rapid fixer and fix approx. around 10 minutes for an APX-25 film. (Twice the Clear time).</p>

<p>Most of the fixers in Kodak's "Processing Chemicals and Formulas" use 240g/L of sodium thiosulfate. As far as I know, that is the hydrated form.</p>

<p>Fixer F5 has:</p>

<p>600ml water @125F or 50C<br>

240g sodium thiosulfate<br>

15g dessicated sodium sulfite<br>

48ml 28% acetic acid<br>

7.5g boric acid crystals<br>

15g potassium alum<br>

water to make 1L.</p>

<p>I suspect that is close to the Kodak fixer that you buy.</p>

<p>There is also non-hardening F24,</p>

<p>500ml water at 125F/50C<br>

240g sodium thiosulfate<br>

10g sodium sulfite, dessicated<br>

25g sodium bisulfite<br>

cold water to make 1L.</p>

<p>In this case, it specifically recommends all chemical steps not higher then 68F/20C, I presume due to emulsion softening.</p>