Change took place at the factory 31 December 2005. How long it took to work it's way through the supply chain is something else.
No doubt much of the world's remaining supply has been used to melt ice over the last week
Announcement from Dow (affects ALL Dow CaCl2 products)
http://www.reefwerks.com/media/August2005.pdf
I don't know what Tetra food-grade costs, but I found reagent-quality at $5/lb in bulk online at:
http://www.spectrumchemical.com/reta...uct_id=5561538
I'd think Tetra would be less than that, but $5/lb with no worries isn't bad either.