All mine are mounted and I have always grown mine mounted. In my opinion, tillandsia need very bright light and during the spring/summer, all mine are outside, hanging under oak trees. They may get a few hours early morning sun but more likely, will get several hours of late afternoon sun. Since I grow lots of tropical plants and several hundred are orchids, my tillandsia get watered every time my orchids do. During the hot months (and they are outside), that may be daily. During the fall/winter months, they will either be in greenhouses of in my solarium. Again, they'll get watered when everything else does. That could be every other day or every few days. It just depends on the amount of light they are getting (cloudy/sunny) and the temperature. I do run several fans in all my greenhouses, so there is air movement 8-12 hrs. a day, helping to dry all my plants out between waterings.
Why don't you try draping some Spanish moss near your plants? This is a tillandsia after all and having some near the other tillandsia raises the humidity. Most of my Spanish moss stays outside year 'round (though I was told by "experts" that I couldn't grow Spanish moss here (gets too cold). Lots of it is draped over plants in baskets/mounted, and thus will be in the greenhouses over the cold months. If Spanish moss grows, your other air-plants will do well.
