Capacity of F-24 fixer

[luxikon]

I made my F-24 nonhardening acid fixer from scratch. I wonder how many rolls of 120 film or how many cm^2 of paper (RC) one liter will fix?

 

[nworth]

About like F-5 or Kodak Fixer. The amount of thiosulfate is the same, the amount of preservative is increased a bit, and it has no hardener. pH is about the same. It should have roughly the same capacity as regular sodium thiosulfate based fixers.

 

[Anscojohn]

Not an easy question to answer as this will vary depending upon the types of emulsions. Probably a safe guestimate for a 24% solution of hypo is no more than 20 rolls of 120 or equivalent surface area per liter.
The "rule of thumb" is to time the point of clearing of the first roll of film you fix with fresh bath. When the clearing time for film reaches twice that original time point, discard the fixer. Most people use a hardening fixer for film, though, rather than F-24.
I use two fixing baths in succession for fiber-based paper; and use a product called Edwal Hypo Check to test the fixer, rather than keep count; but I assume about the same amount of surface area with RC as for film would be somewhere about correct .

 

[mrred]

I know this is an old thread......but

Adding 50g/l of ammonium chloride makes Fixer 24 rapid. Does it add anything to the capacity?