Quote Originally Posted by Ian Grant View Post
Tiny particles of iron in water can cause these problems, I have seen it happen, the particles react with fixer to form a weak bleach and dissolve.

I use and love foma and this is the same problem I had. Clean up your water and it will go away.

Note: I am cheep. I use distilled water to make my chems, but I got a Britta filter and some jugs for working water (including pre-soak and wash). This was enough to make it work.