Question

orchid   Dear Sir,

 May I know why are the lower leaves of novelty phalaenopsis turning yellow? I watered it moderately, followed by misting every morning. It is grown at the spot in my high-rise balcony where it receives few hours of indirect(sometimes direct) afternoon sun. I hope it's not root rot? Is it possible to grow phalaenopsis orchids aerially ( ie without any potting medium) ?
Will further attach pics for your perusal.

Answer
Alfredo, it could be root rot, but, to be sure, you will need to unpot and check roots to see  if any are mushy.From you picture I noticed that you have you have placed you orchid pot inside of a decorative pot. This can be a problem, if any water sits in the bottom of the decorative pot. This arrangement is fine as long as you remove the orchid pot from the decorative pot when watering and allow the potting mix to drain for an hour or more before replacing it back into the decorative pot.  Phalaenopsis need an extremely humid atmosphere to establish themselves on a mount and be properly maintained on that mount.