how to encourage spiking/flowering???

[Ray]

Adding to Ted's response, you really cannot "encourage" blooming, per se. What you have to do is eliminate things that discourage blooming, and provide the plant with adequate conditions for it to grow well - food, water, light, temperatures, etc. - so that when it is ready to bloom, it has the stored resources to do so.

I would recommend that you NOT let a mounted phalaenopsis dry out between waterings.