Adding additional lighting
 

I have Catts, Dends and Phals in my south facing window. I get plenty enough light,,alittle over 3500fc at window,,,but when it is cloudy out I get alot less...
Should I supplement with lights ?
Maybe a couple CFLs?
I know it is not always sunny in nature,,so just asking....

I think it would depend on where you are living and how often you get cloudy days. If you are located more north then with the shortened day length in the winter you may need lights anyways.
I don't know how long you've had your orchids, but if you've never had any troubles blooming them then maybe lights aren't necessary. But like I said, that depends!

Much as I'd love to sell you some lights, at 3500 fc, you need to supplementation, and some cloudy days are going to be of no consequence.

Doesn't it get cloudy in nature?

that is what i thought,,,and people that grow in greenhouses have to put up with cloudy days,,,yesterday it was sunny and over 4000 fc at the glass,,,,i wonder what summer will bring....