Answer: This plant is sensitive to fertilizer salts which can build up in the potting mix over time and also to the fluoride and chlorine that are often added to municipal water. I would suggest you try watering with saved rain water or distilled water, and also try leaching the soil. To do this, water heavily so the water is running through the soil and allow it to drain, then repeat several times in quick succession. Then return to a normal watering schedule. Fertilize only lightly during the growing season of spring to fall, and leach occasionally to prevent buildup re-occurring. In the meantime there is nothing you can do about the tips once they have discolored, you could neatly trim them off to try to make it look better. If you cut at an angle it is a little less noticeable that you have done so.
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