Question
What does my ponytail palm need? A white fuzz (a fungus) is forming on the
leaves and the lower leaves are getting brown but don't pull off easily. I also
have this fuzzy white stuff on a neighboring plant. What should I do? Water less?
Water more? Today I used one drop of Dawn detergent in a container of water to
wash off the leaves and put the plant outside (temp close to 60 and rising)

Answer
You didn't give me a huge description to work with, however I would say you might have a mealy but problem or just fungi. I would recommend cutting the leafs off with a scissors and transplanting it to new soil and let all of the plants in your house completely dry out just in case of a mealy bug problem. The Mealy Bugs go into moist soil and lay eggs, so, if you let your plants dry before watering, they should die.
Best Wishes
Samuel