Sodium sulfite or bisulfite??? You would be using Sodium sulfite, as bisulfite is slightly acetic, and mainly used for tweaking the pH, to put a solution in a different working range...
Steve K
Sodium sulfite or bisulfite??? You would be using Sodium sulfite, as bisulfite is slightly acetic, and mainly used for tweaking the pH, to put a solution in a different working range...
Steve K
Penta thio for a gallon would be 960 grams (roughly 4 x 250g), and 4 (I will equate liters to quarts here) liters x 15g = 60 grams sodium sulfite per gallon by that recipe. However, I could certainly cut back on the sodium sulfite. Maybe see what effects are at 100 or 60 grams per gallon.
Labrat, I don't put bisulfite in the toning process fixer, I was referring to it being used in fixer 24 and maybe that is why I don't get the cloudy fixer.
Yes you correct your calculation 4x15=60!
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Ok, I appreciate the input. I am going to continue to use my current "toning" fixer for another 50 equivalent 8x10s, toss it, and make the next batch with 60 grams sodium sulfite for the gallon with Distilled Water! I'll see what happens. If my present fixer gets more cloudy, I will toss it before continuing. BTW, there is no sulfur/rotten egg smell. Greatly appreciate the input guys!
At the risk of being incendiary, I quit using pure Hypo for toning, and just use TF-4 before fixing, born out of necessity once, long ago, when I had no hypo. As I recall, the issue was supposed to be staining, but several hundred prints later, I have never stained one.
If they're not archival, well, I'm not sure they deserve to outlive me anyway. And they all look good stored in the boxes so far.
My 2 cents.
Bruce Barlow
author of "Finely Focused" and "Exercises in Photographic Composition"
www.brucewbarlow.com
Distilled water is a good idea, or you can add a calcium sequestering agent, or you can lower the pH a little with a small amount of bisulfite/metabisulfite (something like 5-10g bisulfite per 100g sulfite).Originally Posted by steve hartsfield
The reason calcium sulfite is not precipitated from Fixer 24 is that it is mildly acidic (whereas your hypo+sulfite formula is fairly alkaline).
By the way this is one reason why most commercial hypo clearing agent formulas aren't just plain sulfite. In addition to sequestering agents, they are typically formulated to be roughly neutral or slightly alkaline in pH.
The sulfur smell from fixers comes from sulfurization, which happens under more strongly acidic conditions.
Chlorine spikes in tap water would be a different matter. In that case I would simply avoid using tap water for mixing chemicals. Keep it simple with distilled/deionized water.
When going to the grocery store to buy distilled water, I make sure the label says "Steam Distilled".
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