Brown leaf tips on houseplant

Q: My very large 'Painted Princess' indoor plant has developed brown spots on some of its leaf tips. I have not moved it or changed its watering pattern. What is the problem?
A: 'Painted Princess' is a very nice silver-variegated form of aglaonema or Chinese evergreen. Browning at the tip is almost always related to watering - either the frequency or what's in the water. I'd put my money on the second one.

A lot of houseplants - Chinese evergreens included - are sensitive to fluoride in water. That's a common element added to public water to prevent tooth decay. In plants, though, regular doses can inhibit water uptake and cause the same kind of symptoms that drought does.