hey!!!! i was just asking this same question about this stuff earlier today!!! i was told it was diatoms...a type of algae! how new is the tank? i was told it was common in new tanks, after they had completed the cycle... when you move the plant does it look like dust particles in the water? if so, thats what i have too.... i did a water change and tried to get rid of it, and i will continue to do that till it goes away... i have been told it will go away on its own.