Moving to a grow tent

[Dusty Ol' Man]

No, no! Not me! My orkids. I know, but I'm starting to treat them that way. Anyway, I have appropriated from Mrs. Dusty this grow tent since she hasn't used it in quite some time. I have two new heat mats and trays to use for humidity. I have a couple questions for you tent users. First, with two trays containing water and rocks on top of heat mats, do you think the humidity will be raised significantly? And second, would the evaporation of said water create enough air movement, or should I employ a fan? All of your learned opinions are valuable to me, so feel free to let the comments fly! I have found the lighting I will use, but have yet to order it. This will house two phal hybrids, four large dendrobiums, and, if I can make it work, a hospitalized vanda in a vase. I have a place for a few mounted minis, also.