Pothos: brown leaf tips
Pothos is not fluoride-sensitive, so brown tips here usually mean the pot dried out hard at some point, or fertilizer salts have built up in old soil.
Working through the causes
Start with the first one — on pothos specifically, that's the most likely explanation. Each entry below names the observable that separates it from the others.
Inconsistent watering common
How to tell: Tips brown after the plant has been allowed to dry out hard, then watered heavily. Often paired with some leaf drop.
What to do: Water on a consistent schedule for the species rather than waiting for visible distress.
Fluoride and salt in tap water the overlooked one
How to tell: Crisp brown tips, often with a thin yellow halo between the brown and the green, on a species known to be sensitive: dracaenas, spider plants, calatheas, peace lilies, parlor and areca palms. Damage accumulates slowly over months and appears on older leaves first.
What to do: Switch to distilled water, collected rainwater, or reverse-osmosis water. Filter pitchers do NOT remove fluoride. Flush the pot first: run water through it for two to three minutes to leach out the salts already accumulated in the soil.
Fertilizer salt buildup common
How to tell: Brown tips plus a white or yellowish crust on the soil surface or around the drainage hole, on a plant that gets fed regularly.
What to do: Flush the pot thoroughly with plain water several times, then feed at half the label strength and less often.
Genuinely dry air real, but over-diagnosed
How to tell: Whole leaf EDGES crisping, not just the tips, on a species that truly needs humidity — ferns, calatheas, alocasias — usually in winter with the heat running.
What to do: Group plants together, use a humidifier, or move it to a bathroom with a window. Misting raises humidity for only a few minutes and is not a real fix.
Plantroster keeps every photo and every diagnosis for a plant, so "sun-scorched" becoming "sun-scorched and mite-infested" three days later is visible instead of lost.
Track this plantQuestions people ask
Should I cut off the affected leaves?
Damaged tissue never turns green again, so removing it is cosmetic — do it if it bothers you, using clean scissors. What matters is whether NEW growth comes in clean. That's your read on whether the fix worked, not the old leaves.
How long until I know it's working?
Give it two to three weeks. Existing damage won't reverse, so you're watching the newest leaves. If those still come in affected after three weeks, the cause you treated wasn't the cause.
More on pothos
General horticultural guidance based on visible symptoms. A photo or a description can't rule everything out — when a plant matters to you, check the roots before acting.