Question
    why are my tropical houseplants drying and brown on the ends of the leaves. They are watered once a week, and leaves are misted. they get plenty of sun and also have plant light.

Answer
Brenda,

I have found the problem to be caused by too much water. You cannot just water once a week. Plants roots breathe thru their roots. They need alternating periods of wet soil and dry soil so the roots have a chance to breathe in carbon dioxide thru the soil. The plants with brown leaf tips need to dry out totally between waterings. Even when the surface of the soil is dry the soil lower in the pot may be moist or even soggy. The best way to tell if a plant is dry is to pick it up, if it is light weight it is dry, if it is heavy it is still moist.

If you tell me which plants are having this problem I can give you more specific instructions. Good luck.

Darlene