Help! Ive had my rattlesnake plant for about 2.5 years. It has always been in a self watering planter and I only use distilled water; I fertilize infrequently as I have noticed that it is very sensitive to fertilizer. It started to randomly get browning/yellowing leaves; Some start as spots while others it starts at the edges and spreads. I am thinking it is something fungal but before I use a copper fungicide, I wanted to get others thoughts on what it might be as I know using copper fungicide when its not needed can do more harm than good. I checked the roots and they are not only good but there are several pups that are getting ready to break through the surface. Thoughts?