What a weird thing to happen. Sorry for your distress gbeef - and glad to hear things may make a full recovery.
FWIW, I've always used this one:
http://www.jlaquatics.com/phpstore/s...ct_ID=mc-hfast
.. because every LFS in town has it. Easy to replace. I've used the Tunze and the Deltec before in the past because of the whole "it looks like coraline!" claims, but didn't bother replacing them when they got spent. Because 1) pain to mail-order 2) "more expensiver" (especially when factoring in things like "all I need is the epoxy so can't make a $100 purchase...) and 3) the stuff didn't retain suppleness very nicely - it was more like squeezing marbles than kneading putty. And come to think of it, I think one of them DID cloud my water (I forget which one).
The white stuff ... OK so it dries white. But big deal - it gets covered in coraline sooner or later. Never had an issue with water clouding up or fish or corals reacting to it in any way.
Good luck!