Hi Kathy,
Pachira aquatica is a recent introduction that has suddenly become very popular. It has not yet proven itself as a hardy and reliable potted
plant and it may never. It can be quite tempermental and is not forgiving of temporary lapses in care.
It should get lots of very bright light with protection from more than a couple of hours of direct sun each day. An east or north windowsill would be good.
Watering depends on how it is potted. If it is quite potbound, then the soil should be kept moderately moist, allowing only the surface of the soil to dry in between waterings. If it is not potbound, then allow the top quarter of the soil to dry out before watering. Make sure it is potted in a pot that has drainage holes.
Keep it as potbound as possible and fertilize very sparingly or not at all.