Actually I have had this Dendro in my system for over a month now. I have put Joe's juice in there before.
In addition to that, the dendro itsself is not deteriorating at all. After releasing the white stuff, it went back to normal with flowing tentacles etc like it always does.
There are a few people on wet web media whom have had the same thing happen with their dendros and sun corals.
http://www.wetwebmedia.com/dendroreprofaqs.htm
Because my dendro is acting normal now and looks normal and is even taking food, I am not going to worry.
Also I looked at your article. It is for DendroNephthea.. not DendroPhyllia. Two very different corals. But thanks for the info, I was considering one of those corals in the future, so I will keep that article for reference.