Yellow streak at end of Phalaenopsis leaf

[ELORCHID]

I noticed that a couple of my Phals have developed a yellow streak at the end of their leaves, not sure whether its a cultural problem or virus. I've attached a photo of one of the leaves. This particular plant was repotted (in a bark mix) about three months ago after it finished flowering and is currently developing new buds, I'm watering every 7-10 days with tap water and fertilizing every 3 of 4 watering, its also sitting Approx. 1.5 feet from the window. Thanks in advance for all your help.
Sorry for the picture quality but it was taken with a 3.2 megapixel Kodak EasyShare camera.

[RosieC]

I'm afraid I can't help. Not seen anything like that before. Just giving you a bump in the hope someone else will be able to help

[nutgirl]

I have a couple of phals that do that. Don't know why, it doesn't seem to hurt anything.

Maureen

[ELORCHID]

Rosie, thanks for the bump, I was getting desperate and just about to bump myself. Thank you Maureen, I can now breathe a little better knowing that it might not be a big problem.

[Zoi2]

I also have a phal with a slight rim around one leaf. It has been there for the last year or two and doesn't seem to be a problem. I thought I might have given it too much sun.
Joann

[trdyl]

This seems quite normal for some Phals. I have a couple that do this.

[Izzie]

I knew I saw reference to this somewhere- in Ray's article about plant nutrition- Fertilizers & Plant Nutrition
Apparently a calcium deficiency can cause yellow leaf margins.
I have a few phals that have the same thing- nothing to worry about.