I've had some problems with a few plants that have stunted growth, like small leaves & certain plant leaves not splitting like they're supposed to, wimpy stems, barely any roots, etc.

I briefly mentioned them on this thread:

http://forums2.gardenweb.com/forums/load/houseplt/msg0422400126456.html

What could be the problem; lack of or too much light, not enough or too much water, what?

This has been going on for years, not just in an arid climate with very hard water (2004-present), but also in a humid climate with normal water (2002-2004), & another arid climate with normal water (1996-2002). Each spring they've been repotted in different potting mixes (all plants received the same mix, but the mix was switched to something different the next year) & the same size pots because they haven't been growing, in fact they're shrinking, & they haven't sat in the same light each time. It's all too confusing.

Thanks!