It is just planted in a very large pot. It is sitting in indirect sunlight. It is taking in a lot of water and then leaves turned yellow, so I stopped watering. Should I keep watering it, and does it require drainage because of being in the pot? I guess that's 3 questions.
How Much or Little Sun Does Hibiscus Need Planted in a Pot?
Certified GKH Gardening Expert
It does require drainage, no matter what. If you are growing it indoors, it will need to be watered when the soil is dry to the touch on top. Outdoors, they normally need to be watered daily if the pot has proper drainage.
As to the sun. They prefer full sun for best blooms, so as much sun as you can give them is great. At minimum, you want at least 4 hours of sun, but you will see diminished blooming.
The leaves will turn yellow for a wide variety of reasons. This article will help with that: