Plants in lower light need less fertilizer or the tips of leaves start to shrivel. Flush the pots with plain water occasionally to prevent deadly salt buildup. Many orchids aren't heavy feeders, so feeding every couple of weeks is enough. They have an indefinite life span, so fertilizer isn't critical as it is with an annual. One months missed fertilizer won't stop blooming or mortally wound a plant that can live a century or more, given good care.
Proper light is more important for good blooming than a rigorous fertilizer regimen.
These are the perfect plants for permanent indoor growing. Natural light in a sunny East or South window, a bay window, sun porch, or bright plant room is usually adequate. Harsh South or West windows may be too bright and hot. Simply, place sheers or another plant between them and the light source when the light is too intense for these plants. Watch the leaf color for clues about how your growing area rates with these plants.