in which case i would say replace the vermiculit with perlite. moisten it to 1 part perlite, to 0.8 parts water, then place the same ratio in a sealed container with the eggs, it will keep the humidity correct. open daily for air exchange, but breifly so as not to allow humidity to escape, or the temp to drob significantly. the best temp for leopard geckos is around 80-82 for females, 82-84 for a mix of male and female, and 84-86 for males. i would reccomend a temp of 85*F, because you will get a good range, and if it changes by a degree or two, no harm will bee done. near hatching time, i would put holes in the top of the tub, but mist everyother day.
hope this helps