Donald,
Fixing RC prints is really similar to fixing film, and I imagine the amount of dissolved silver that the fixer can stand before it becomes ineffective is similar too.
It is the fiber-base prints that need less-used fixer, two-bath fixation and longer wash times to be optimally permanent. Ilford states that fixer for film (and RC prints I'm assuming) can have a dissolved silver content of up to 8-10g/liter. Fix for fiber base prints for commercial use (i.e., not processed for optimum permanence) can stand up to 2g/liter and fixer for prints processed for optimum permanence can only have 0.5g/liter. I believe Haist (Kodak) liked even smaller amounts than these.
So, you can see that a film fixer (and fix for RC prints probably) can contain 10 times more dissolved silver than the final fix for fiber-base prints if we want optimum permanence. That's why the clip test won't really work for testing fixer when using fiber-base paper; it's just not sensitive enough. For RC prints, however, it is likely just fine.
I don't know where you are in NC, but when I was on a septic system, I collected my fix and took it to a local photo lab for silver recovery, five gallons at a time. They took it gladly, because they got the silver. If you can find a traditional photo lab or photo finisher in your area, they'll likely do the same.
Best,
Doremus
Fixing RC prints is really similar to fixing film, and I imagine the amount of dissolved silver that the fixer can stand before it becomes ineffective is similar too.
It is the fiber-base prints that need less-used fixer, two-bath fixation and longer wash times to be optimally permanent. Ilford states that fixer for film (and RC prints I'm assuming) can have a dissolved silver content of up to 8-10g/liter. Fix for fiber base prints for commercial use (i.e., not processed for optimum permanence) can stand up to 2g/liter and fixer for prints processed for optimum permanence can only have 0.5g/liter. I believe Haist (Kodak) liked even smaller amounts than these.
So, you can see that a film fixer (and fix for RC prints probably) can contain 10 times more dissolved silver than the final fix for fiber-base prints if we want optimum permanence. That's why the clip test won't really work for testing fixer when using fiber-base paper; it's just not sensitive enough. For RC prints, however, it is likely just fine.
I don't know where you are in NC, but when I was on a septic system, I collected my fix and took it to a local photo lab for silver recovery, five gallons at a time. They took it gladly, because they got the silver. If you can find a traditional photo lab or photo finisher in your area, they'll likely do the same.
Best,
Doremus
