Hello everyone. This is my first time posting in this forum and I am hoping to get some help in identifying the problem I am experiencing with my Fittonia. As you can see from the attached picture, the leaf tips are turning brown and drying out. They are hard to the touch and crumble if pressure is applied. I water regularly but allow the soil to dry slightly between watering. I also place it in a gravel lined saucer for humidity. It does not receive direct light but does get filtered light. I did add fertilizer spikes to the pot and think this may have something to do with it. Any thoughts or comments would be greatly appreciated.