Well This is my very 1st chance to help out here, I work in a Laboratory and we have to keep some chemicals
in a controlled environment, we call it a "Jungle Room" and/or "rain-forest" museums use some of these
techniques. were as the RH has to be maintained at 75 % . you can mix in a small bowl or a cut off milk jug
100 mg of Calcium Nitrate add water until the Calcium N02 is dissolved, to bring RH up add Tiny amounts
of the Calcium, u won't need a fan just place jug in In side, you will need a Hygrometer, you can find what
you need ,, google Lab supplies, also google "make your own humidity chamber" they will list all your info
and once desired RH is achieved it will last for months Hint: put some kind of plastic lid on it and poke holes
in such has using small coffee can' This will rust later on however, GoodLuck!