Bird of Paradise:
BoP do best with southern/western windows, but unobstructed north/east windows can work. Ideally, it would like 4-6 hours a day of bright light. Winter makes this difficult, so just do your best. If you don’t have even light, you should rotate the plant every two weeks or so.
Realistically, every 10-12 days. However, frequency will depend on how warm the space is, how much sunlight the plant receives, how much humidity there is, and whether or not it's by a heat vent. The most effective method is checking the soil at the bottom of the pot. If the soil is moist, leave the plant alone. If it's bone dry, then it's ready to water. In general, you should thoroughly saturate the soil, and let it fully dry before adding more.
Keep in mind that:
10" Pot = 3 gallons of volume. Plant needs 1-1.5gal of water.
12" Pot = 5 gallons of volume. Plant needs 2-2.5gal of water.
14" Pot = 7 gallons of volume. Plant needs 3-3.5gal of water.
You will need a catch try to hold water that will eventually seep through the bottom.
Prefers 35% - 45% humidity. If you don’t have a a humidifier, I’d suggest getting one - cheap ones work just fine. Heat vents will dry the air out, so you need to counteract that. If you notice brown, crispy edges on the leaves, then it's not receiving enough humidity.
All plants should be repotted within the first two months.
1) The soil in the pot was chosen to offset the heat/sunlight in Florida. This soil is too dense for a Chicago home/apartment, and will potentially contribute to rotting issues if you don't decrease watering.
2) The soil in the pot has realistically been there for 1-1.5 years. While there are some nutrients present, the plant has likely used up most of what was originally present.
3) If you can see the roots at the bottom of the pot, then you absolutely need to repot it right away. The feeder roots that seek out nutrients / water must have something to grow into. If those roots dry out or die, it confuses the plant. So, when you repot, make sure to add 2-3" of soil at the bottom. You need to create a buffer zone of soil for the roots to grow into.
It’s beneficial to wipe the top/bottom of the leaves every few weeks to help prevent pests and remove dust.