Yellowing Leaf

[aksquish]

I’ve had my Phalaenopsis Orchid since May 5, 2011.

I keep it on a counter above my desk. There is flourescent lighting for 10 hours a day, non-UV bulbs. There is an East or West facing window, but I’ve not decided if I want it that close to the glass. I live in Alaska and the winters can get below zero. So most of the year it is too cold near the window. It is in a clear plastic pot with slits in it. I’ve placed it in a tray with water, it sits on rocks and no water touches the bottom of the pot, ever. While I am at work I have a fan on low that is positioned to blow at the Orchid, which I rotate the orchid once a week so not any one side is over aired then another.

I’ve been watering it every 7-10 days. I wait until the spongy moss stuff looks dry and is dry to the touch. I never pour water over the leaves.

It was in the middle of blooming when I got it so I haven’t fertilized it, nor repotted it as the articles I found on line several of them agreed to not fertilize nor repot while blooming.

My concerns are with a leaf that has the tip of it yellowing. It was yellowed when I got it and has since started moving a little bit further down from the tip of the leaf. There are 6 strong dark green leaves, two leaves that are on the bottom closest to the media and not exposed to very much light as they are practically touching the leaves above them. There is another large leaf that appears to be lightening at the tip as well.

The roots that I can see look mostly healthy. There are a couple that might need to be trimmed if I repot.

The orchid has since completed its blooming. I’m not sure what to do now.

What can be causing the yellowing? Should I repot with bark instead of the spongy moss? Should I trim the stick for future blooming?