I'm a windowsill grower and adore my phals....however, there is light, then light. If you have an eastern exposure with trees or a house blocking some of the light, then you are apt not to have enough. Generally, if you can bloom an african violet in the light, then you can bloom a phal. Here, I put mine in the southern window during the summer as the sun is so far in the north here at that point....if you put your hand over the phal and see a definite shadow with difuse edges, then you probably will be ok, but I agree, I'm betting you will need supplimental light.

As far as watering goes....everyone is correct...slightly damp...think a sponge wrung out until almost dry..not sopping. I like to use the skewer method with my phals...if you can feel moisture on a skewer (stick it in the media in the middle, pull it out and run it across your cheek or upper lip which is more sensitive...if it feels cool/damp don't water....very slightly damp or dry, water). Most folks overwater phals.

I agree with Mike...for most people s/h takes the guess work out of it and the Phals love it.