I've heard that used darkroom chemicals make good fertilizer? Is this true?

Question

if not how can I dispose of them without pouring them down the sink?

Answer 1

I have heard used fix is chemically similar to fertilizer except for the silver. Spent CD can be poured down the drain. The other chemicals will have silver in them, and should be recovered before disposing. You can recover it yourself by pouring it in a plastic bucket with steel wool, but in small amounts the local haz mat facility might take it, or you could ask the local photo lab or community college photo class if they could dispose of it. (This is one advantage of digital, less chemicals to deal with.) I would hesitate to pour lots into a septic tank, but in the city sewer the de-silvered chemistry is no problem.

Answer 2

Developer, stop bath, hypo, and especially fixer should not be used as fertilizers. The reason for fixer is because of the high concentrations of silver which is a hazardous waste, and when introduced back into the environment can harm wildlife, as well as humans if it is consumed. Dispose of fixer by going to your local photo store, or try the steel wool method. I would suggest the local photo store because you will still have to deal with the chemical sludge.