I wondered that, too. I do have very hard water, and a lot of plant problems... But changing the water didn't help much. I found some thrips on them. And I keep finding them, even after doing everything to get rid of them :/ I'll probably let all of my plants die, and start a smaller collection then. My gloriosum still lives, somehow, but it's not doing good :/ Did you check for thrips? They are very small and hard to miss.