Yeah with the humidipak it will slowly increase humidity, but if you want quick humidity increase just get a small piece of wood, the size of a coin, like a 1€ coin, and let that wood sit in water, then pick the wood after its soaked for about 15 minutes and place it inside regular weed baggie and place that baggie closed inside the jar (baggie closed ok? Hum?) And watch the humidity go up, next day it will be fine (if you can fit your whole hand inside the jar, otherwise the jar is too small and you should take a look at the end of the day.)
Hope it helps and if you don't mind chosing answer it helps a lot in grower of the month competition.
Thanks and good luck growmie.