Black leaf tips

ash.211278

Im an amateur plant parent and am wondering if anyone can identify what has happened to my corn plant. I bought it with these black patches on the leaves, the yellow lining has since appeared. Any advice appreciated!

pansyface

Possibly fluoride poisoning from tap water.

See here:

https://pnwhandbooks.org/plantdisease/pathogen-articles/nonpathogenic-phenomena/fluorine-toxicity-plants

Try watering with rain water and see if the new leaves are happier.