I bought a blooming orchid for $10 at Home Depot, of all places, a
couple of months ago. It has one flower left; the others have dropped
off. I assume the last one will fall off pretty soon. Is the plant
spent after it blooms, or can I keep it going and expect it to bloom
again in my lifetime? I don't know what kind of orchid it is, but I'd
call it a moth orchid rather than a slipper orchid. It has 5 or 6
strap-like leaves.

It is planted in what looks like a roll of half-rotten tree bark instead
of chopped bark and/or orchid mix, so I'm not sure how I'd replant it
other than set it a little deeper in a bigger pot. If I try to remove
the old "soil" I'll destroy most the the roots.

I've been watering it by soaking the root ball for about 5 minutes and
then draining it, and letting it dry out completely before watering
again. (I think it lost a few blooms when I let it dry out too much.)
I haven't given it any food yet. Should I be using distilled water (or
deionized, or rain water) so salts don't build up?

Thanks,
Bob