Question
I have about 2 dozen orchids, mostly Phalaenopsis of various sizes planted in bark and kept indoors.  Some I bought blooming a few months ago - some are years old.  I feed them every other watering or so, in tepid water, with Schultz's orchid food - 19-31-17 - about 1/2 tsp to a gallon.  But only one has bloomed in the last year.  Is there a way to force blooming?  Most are in original pots. They get bright light, no sun, dark at night.  Any suggestions?

Answer
Jeanine, Phalaenopsis usually bloom only once per year so let's address the plants that haven't bloomed for several years.  I'm going to assume that your plants are growing well.  The reason I'm making this assumption is that orchid potting mixes deteriorate over time which then leads to root rot and decline in plant vigor. In general, phalaenopsis should be repotted annually to maintain plant vigor.  However, with good plant vigor, should come flowering.  Failure of a healthy plant to flower is commonly the result of insufficient light or lack of a daily temperature gradient of 10-15 degrees. Leaf color is a good indicator of amount of light the plant is receiving. Leaves should be a light green to promote flowering.  Leaves that are a darker green may grow well but don't receive enough light to generate the hormones and pigments necessary to flower.  The ideal temperature should vary from a low of 65 degrees to a high of about 80 degrees during a day. A minimal variation of 10 degrees may be sufficient (eg 65 degrees at night to 75 degrees in daylight).  Since you are using "bloom booster" fertilizer, that should be fine.  If you grow in a window, phalaenopsis do best in an east window where they can get morning sunshine. Many phalaenopsis are responsive to daylight duration.  Since days are lengthening, typical phalaenopsis should come into flower spike in March-May.