Question
I received a moth orchid for Mother's Day. It was from Home Depot or Lowes. It is planted in bark and flowered beautiful for about 8 weeks. It dropped it's flowers and I cut the flower spike back to about 6 inches. I put the pot on rocks and fill the saucer once a week with water. A few of the leaves now have thinner, browner ends. What next? I think it looks OK. Do I fertilize? Repot? Water differently? How do I encourage more flowering?

Answer
Amy, congratulations on your orchid.  First, you need to repot in an orchid potting mix.  This is a specialized potting mix for orchids and has fir bark and other ingredients in it.  Usually Lowes and Home Depot carry hobby bags of it.  You may need to add perlite to it as these mixes are kind of skimpy on that ingredient.  Perlire is readily available at garden centers but do remove the dust and finest particles before use.  Use about 3 parts orchid potting mix to one part perlite.  Soak the amount of orchid potting mix you think you will need overnight before use.  Be sure you are repotting to a plastic pot with lots of drainage holes.  Remove the plant from its pot and rinse off the roots.  Remove any mushy or stringy roots as they are dead.  Healthy roots are firm and turn green when wet.  Rotate the pot as you lower the roots into it (this is to reduce damage to the roots) and start adding the wet potting mix to the pot.  Tap the sides of the pot as you add the potting mix.  Be sure you are doing this in a location where the excess water can run through the pot.  Set the plant in its pot aside for a day to thoroughly drain before moving it to your growing area.  You should repeat this process after each flowering.  Since the perlite is inorganic it keeps the potting mix open to air movement even as the fir bark decomposes. Do not water for a week and then water thoroughly once per week.  Each time, place the pot where excess water can drain out of the pot and replace it to your growing area only after it has stopped draining from the pot.

If you keep your plant on a pebble tray be sure that the water does not come up to the bottom of the pot as it will wick up into the potting mix and keep it too wet.

These plants usually are on an annual flowering cycle so look for it to  
flower next year about the same time as this year. Sometimes by cutting the old flower spike back to just above a node (ie joint) the node might create a branch in the flower spike.  Many phalaenopsis are day length sensitive so if you keep it in an east facing window that is fine.  If you have it under artificial lighting, put it on a timer to keep the lights on about two hours longer than normal day length.  If you feed it, use 1/4 the concentration recommended on the plant food container.