Mounted Oncidium Question

[prc11]

Someone gave me an oncidium today at my local society and said the plant preferred a lot of air to the roots. I ended up placing it on a tree fern mount. I was wondering if I should just spray the roots well in the morning before I go to school, then water it well once or twice a week. Would that be too much water or too little. Could you tell me how I should water this plant. I was also wanted to experiment this summer and place one of my orchids outside. Would this plant be a good choice. Just in case you want to know the tag says Oncidium Hawaiian popcorn.