my recommendation would be to just go with a external humidifier like mine, but also hand-spray a little bit a few times per week. that will be more than enough to keep the bromeliad happy. I had bromeliads living in that tank for 3 years without a mister. you would be surprised how much water is actually added to the tank via the fogger. they work great.
it is a 180g predatory tank on the other side of the vivarium. here is a picture of all my setups. there have been a few updates since (i.e. trimming back the massive plants in the vivarium, but this gives a overview nonetheless
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