i just moved into a small place that has turned out to be poorly insulated. my millions of houseplants have been keeping the humidity up pretty high--- we discovered a mold problem behind furniture and under the bed last week. we've removed the mold and are going to keep the furniture away from the walls. we also bought a dehumidifier and have it on all the time; it's set at 55% humidity. my question is if 55% humidity is too low for most houseplants. i have quite a variety of plants (african violets, succulents, philodendrons, herbs, dracaena, maranta, bromeliads etc.)... i've heard of humidity trays, but i don't think i can find enough trays or enough gravel for all my plants. i've got my plants crammed together; will this help keep the humidity up around their leaves? thanks! any help will be appreciated.