Photo Engineer
Subscriber
OK, folks...just called the Formulary. The TF-4 vs TF-5 info is in their new newsletter, downloadable from the bottom left column of their home page.
Some features include: no sediment, no odor (since it's not as alkaline, closer to neutral or slightly acidic ph6.5). I was told on the phone that it is not ammonium thio-based.
Please check this again.
PE