I saw some Jeyes stuff today but left it because it didn't say 'pure' or '100%', and gave no indication of dilution.
I might go back and buy it tomorrow. Shall have to pour it into a clear container so I can do the shake test. Then add it to the tank slowly whilst taking readings to 5ppm, I believe...
I can't believe most lfs don't seem to stock it given the apparent demand. Don't lfs owners read the forums?