Pachira aquatica is a fairly new
plant on the market, so there is not a lot of information on how this
plant fares over the long term. Some
plants are more tolerant than others of lapses in care. Time will tell about this particular
plant.
plants often respond very slowly to adverse conditions. A
plant that gets just a bit too much water or not quite enough light will look fine for a long time before the effects of the improper watering or light are noticed. Unless, your refrigerator is right next to a sunny window, then inadequate light over the winter may be the problem.
I don't know how you water your lucky bamboo, so I don't know if that is appropriate for your Pachira.
If there is anough soil to keep the roots moist for three days or more, then there is enough room for the roots.
plants do best when there roots are crowded.