Having used the Silver Magnet for several years (still filling up the first one) I would suggest a separate container to keep things clean. (I'm pretty sure I posted a photo of my setup somewhere in one of these threads.) I use a plastic shoe box with a snap cover to keep the dust out then I pour the fixer through a coffee filter before re-use. I don't know how the fixer is affected by the electrolysis other than if you keep the fixer in long enough that the remaining silver will not register on the test strips, it clears film very quickly. I have seen no issues at all with fixer I've re-used after treating with the Silver Magnet, but after the third time through I take it to the local household chemical drop off just to make me feel better.
If you get a Silver Magnet, get a pack of test strips as well (I tear them in half as you don't need a full length strip).
Where do you buy the Silver Magnet?
Originally Posted by Neal
A fellow on the forum sells them (see the linke from mopar_guy). I purchased mine from Porter's.
Let's get a little perspective on silver recovery. Check out Kodak Publication J-210 "Sources of Silver in Photographic Processing Facilities". It provides an example of how much silver can be recovered by a lab. A lab processing 50 rolls per day, 6 days per week, i.e., 15,000 rolls per year can recover 280 troy oz. of silver per year. At $20 per oz. you could get $5,600 per year for that amount of silver, not including the cost of equipment and chemicals to recover it. But that's for a lab. I typically shoot and develop 60 rolls of film per year. So, proportionally, I could get $22 a year for the silver, not including the cost of recovering it. In other words, it's not worth considering.
On the environmental side, the amount (mass) of silver you dispose to the drain is so small that it's probably not detectable after dilution, perticularly if you are on a community sewer and sewage treatment plant system. Maybe a heavy home film/paper developer on a septic system would have a concern after many years.
depending on where you live one can get into a heap of trouble putting spent fixer down the drain
Originally Posted by mklw1954
i know of someone locally who was fined about $$100k for not complying to the regulations.
not that every local is that strict, its just not nice to your water supply, septic system, pipes, ground water local ecosystem &c ...
kodak made a 180 degree turnaround from the publication that is usually quoted from where they say it is okay
to put the stuff down the drain. another publication from the same source ( kodak ) a few years later ( 1990s)
says do not put anything down the drain.
I tried the bucket of fix and a roll of steel wool. Ended with a bucket of rusty sludge months later. I've got a silver magnet now.
Work with a large printer with which the bleach fixing crashing/precipitating a creamy precipitate out is common (RA-4 process) - I think the replenishment rate is too low, but it's already on the maximum setting.
Here's what it looks like on the filter when that happens. I assume it's silver halide precipitate or some other silver precipitate (doesn't seem to dissolve too well in fresh fix) and worth recovering?
It could be Iron Oxide or Iron Hydroxide. They both have that look and will not dissolve in much of anything.