Phalenopsis leaves turning yellow

[GNV1080]

So, I'm new at this orchid thing and apparently the Phalenopsis orchids are the easiest to grow (according to the guy I bought mine from). Well, I seem to have the most trouble with these guys over the other ones...

I noticed today that the base of my leaves are starting to turn yellow (just the other one that I had). When the other one's leaves turned yellow, I later found out that the roots had rotted out and the rot had carried up to the leaves.

Am I wondering what's going on here and what suggestions y'all might have for me? I have attached pictures as well.

I unpotted the orchid today and got rid of the roots that were no longer attached and generally tried to clean the roots up a bit (I did not cut anything). After that, I repotted it with a loose mix of small stones and orchid potting mix.

I generally water this guy about once every two weeks by soaking it in the sink for 30-45 minutes. I'll also periodically spray a little bit of water on the top of the potting mix in the pot (just two or three squirts). Is this ok?

Am I doing anything wrong?