Since my humidity with a dehumifier still stays around 50-55,60-65% max because It s Winter(Summer 40-35%),I use to put them 3-4 hours behind the window,sun gets through my room because it’s south located and UV from the sun gets Them much more frosty than my lumatek,no chances
-edit:Thank you for the tip,love your knowdoledge,It Is priceless!!