Hi, I tend to mist my Phals anyway as I don't have a great humidity level in my house. Watering to cure suspected dehydration can get you into trouble as you *really don't* want to over water and get root rot - a good watering schedule will plump up the leaves in time and, if not, the plant'll grow nice new healthy leaves while the older ones die off. You could always try having little water trays around the plants to help with humidity if you think that's the problem.
However, if the leaves are thinning down and becoming 'ridgy' it could be due to root trouble - have you had an inspection to see what they're liike?
Don't worry about the lack of chemistry - it might be that you're stressing yourself out by trying get everything perfect, try to relax and you'll get the feel for them as you go along