Dry air (low humidity). Raise humidity with a pebble tray or humidifier nearby. Skip misting directly on the leaves, which can encourage rot on this plant.
What’s causing it
Too little soaking
How to tell
Pink quill dries out between soaks faster than most people expect since it has no soil reservoir, so the tips crisp first.
The fix
Soak it fully once a week (twice in a hot, dry room) rather than relying on misting alone.
Tap-water salts (fluoride/chlorine)
How to tell
A white crust shows on the soil surface or the pot rim, and the tips brown despite even watering.
The fix
Switch to filtered, distilled, or rainwater, and flush the pot occasionally to wash out built-up salts.
Fertilizer burn
How to tell
Brown tips appear with a white crust on the surface, usually after feeding too often or too strong.
The fix
Flush thoroughly with plain water and feed less often, always diluted.
Too much direct sun
How to tell
Dry brown patches or scorched edges show up where strong sun hits the leaf. Pink quill wants bright light and some direct sun.
The fix
Filter the harshest midday sun with a sheer curtain for a few weeks, then reintroduce the sunny spot gradually so the leaves can harden off.
Prevention
Keep humidity up with a pebble tray or humidifier rather than misting the leaves, water before the mix goes bone dry, and feed lightly.