Just got this from Katadyn's web site:

Micropur MP1, which is regesterd with the EPA, is an easy-to-use water purification tablet that is effective against harmful bacteria, viruses and cysts. It is the only tablet currently registered with the EPA that effectively controls cryptosporidium, a waterborne cyst. MP1 has been extensively tested using EPA testing protocols. The test data is summarized below:
Microorganisms Killed Contact Time
EPA Water #1(clear, 20° C) EPA Water #2(dirty, 4° C)
Bacteria 15 minutes 15 minutes
Virus 15 minutes 15 minutes
Cysts 30 minutes 4 hours
Note: Product instructions have a 4 hour contact time. Fulfilling the role of protecting consumers, the EPA requires that packaging claims for Micropur MP1 communicate how the product performs in the most challanging water conditions (water that is very cold and dirty). While MP1 is effective against bacteria and viruses in 15 minutes, it requires 4 hours for cryptosporidium in cold, dirty water. Therefore, labeling requirements include a 4 hour wait time for maximum consumer protection (see chart above).

Looks like I may retire the iodine for good!

They tasted like crap anyway.

Flip