i followed the online information. wait till the soil is bone dry before watering. if in any doubt, wait longer. so i'm watering mine once a week. they are not dead yet. in about 2-3 days the soil is bone dry and i'm letting it go for few more days.
one thing i find funny with one of the thinner one is that it seems to lean toward the sun. they are in part shade right now before i move them to full sun in next few weeks. do they supposed to lean toward the sun? or am i not watering them enough and they are having some problem?
once they are moved to full sun, i'll be monitoring more closely and giving it water after being dried for 1 full day.