Personally I find mine do best directly next to an East window. I found that much less caused the growth to become less compact and the colors to be not as vibrant. Much more than that though I think would cause some nasty sunburn.

I only have a north window, unfortunately.

Newbienew...Where abouts are you located? I would imagine that since Bunnygurl is in a Zone 3 location, that her plants could handle the less intense sunlight compared to a zone 9-10 florida or something. I was under the impression (though I could be wrong) that variegation in a plant means it needs more sunlight that a standard variety would. That being said...the lemon lime and the tricolor could probably handle being right up beside the north window. As for the compacta I would put it a foot or two away from the window. This book a have with me says that if its a northern exposure and you can read comfortably in the day time, then thats fine light

I'm either in a high zone 5 or a low zone 6.

Actually, what I need to know is how far I can keep the lemon line and tricolor from the window.

Thanks for taking the time to answer my post!