Quote Originally Posted by jnanian View Post
marko

according to an apug member who owns leases and sells photo booths
his booths have a process that uses toners and bleaches and things like that ...
maybe thats's what the curious liquids are ...

http://www.apug.org/forums/forum37/5...h-process.html
Thanks,

But this still leaves me slightly puzzled. Looking at the "reversal" chemical list there, I think most of the listed chemicals are colorless, except the potassium dichromate, that I have never used. According to this page, potassium dichromate forms "bright yellowish-red crystals", so the orange/red solution might be it...

Maybe the yellow and greenish solutions are actually contaminated water baths???, with more dilution during washing of the excess dichromate, maybe a pH change causes a shift to a blue/green color of the solution???

OK, now seems there may be another reaction going on in the water baths (see http://en.wikipedia.org/wiki/Potassium_dichromate): if chromium ions are reduced, they shift color from orange to green. Since there will undoubtedly be some cross contamination between baths, the water bath probably contains enough stuff that can be oxidized, to facilitate this reduction reaction.

"When an aldehyde is present the chromium ions will be reduced from the +6 to the +3 oxidation state, changing color from orange to green."

Marco