I don't know what the discolored area might be, but these are not usually great indoor plants without the maximum possible amount of light. So right up next to your sunniest southerly facing window would be ideal. If you use lights, they should be annoyingly bright (for humans), and relatively close to the plant, and on for half the day, ideally. We have a sticky thread about artificial light if you would like some more details.
As for watering, you are going to have to be careful the next few weeks if the plant is in a low light situation. Less so if the plant can see the sun for hours a day through the winter. During the warmer/brighter months I would advise watering to saturation (ie. until water comes out the holes at the bottom), ideally in two or more passes (separated by a few minutes) to get the soil good and wet, and then waiting for it to go dry or nearly dry at depth (not just at the surface). You can try the same approach during winter, but the wait will be significantly longer. A cup of water a week is probably not getting the soil in that zone, but maybe that's better for the next few months, if light is limiting.
The golden barrel and aloe next to it would also benefit from the most sunlight you can provide indoors. The more, the better.
