well not done by them but paid for by them but all the same could be very biased.
Thing is none of the other salt companies are willing to pay for have their own products to be "publicly" tested against the other competitors. I'm sure they have done their own in-house testing and if they were on top they would pay to have these tests done immediately and post them everywhere. atleast I would think so anyways ... So with lack of other proof I guess I am choosing to believe them.
there was also a test done by ron shimik where it did very well.
http://www.reefkeeping.com/issues/2003-03/rs/feature/
and another test where it did better than all the rest but for the life of me i cant remember where it was .