hello,
reading in other board I find this:
www.sciencemadness.org/whisper/viewthread.php?tid=30280
because here people not are too accustomed to buy pure chemicals from a lab chemical co. BE AWARE OF THIS
sometimes the calcium hypochlorite is swapped by sodium dichloroisocyanurate IN THE SAME PACKAGING.
sodium dichloroisocyanurate sound very nasty, but I thing nobody tested it. If is sold like a "copy" of calcium hypochlorite maybe be safe for water in pools but...
the guy woelen say:
"One hardware store has the dichloroisocyanurate, the other has calcium hypochlorite and sometimes they switch over time, probably depending on the margin they can realize with the product."
SO ****ALWAYS**** READ VERY CAREFULLY THE LABELS
ALSO YOU CAN READ: not mix the MMS and HCL (around 30%) in large quantities and under sunlight!! danger of explosion
well without fear but with common sense