how come it isnt outside?

first thought. winter leaf drop being by the window or overwatering. Combination of both maybe. Could you tell a bit more about it? Soil type, fertilizer used, watering habits, the climate.

mike

Thanks Mike--
Tree has been healthy until now. Use Treetone monthly or so. Water weekly. Currently in partial sun inside by a window.

Should I place it outside? re-pot it?

Thanks,
mark

if the temps are above 50 it should definitely be outside. whats the soil like? is it regular potting soil? how long has it been in it? does it drain well?

Of all the citrus cultivators that can be grown, grapefruit is the least adapted to container culture. Grapefruit is a large tree, requiring a hot, humid location to do well. Therefore, the best grapefruit grown in the USA are grown in the Indian River district of Florida, and also in the hot and humid valleys of southern Texas in the Rio Grand valleys. Your tree, in fact any grapefruit tree, has a very hard time doing well when grown inside an apartment, receiving the limited light that comes through a window. Looking at your tree I can see that it is not doing well. Unless you can duplicate the required environment it will be difficult to produce a strong healthy vibrant tree.