> often use a supersaturated solution of sodium thiosulfate, which the crystals
> can be bought at a photographic store. If someone wants the approximate g/100
> ml email and I'll send it along.
I once worked at a chemical supply place in Melb. A 25Kg bag was worth
< $5 for me. Probably about 10-15 for someone off the street. If there
is a few of you you could just split it and still have heaps. You really
don't need very much of it.
Tootles
Peter Unmack