What is the problem with my desiccant experiment?

Ok, so here's some context. For my experiment, I wanted to see which desiccant would absorb the most water in a low humidity environment (30% RH). To conduct this experiment, I placed the desiccant into a box with a saturated salt solution (Magnesium chloride) and then placed the box into an incubator to get a constant temperature. Due to practical restraints (and poor planning), I was only able to fix the mass of desiccant to 10g and not the moles of desiccant. I also left the experiment for over 12 hours. 


I expected by results to be similar to results I found on the internet but it was nowhere close. My results were:


* Silica Gel: 5.84% of its mass absorbed
* Calcium Chloride: 7.77% of its mass absorbed
* Calcium Sulfate: 6.87% of its mass absorbed
* Lithium Chloride (aqueous): 3.02% of its mass absorbed


I'm not sure why my results are so inaccurate I guess. Is it because I didn't use enough desiccants, or is it because I didn't have a direct air flow? I really can't figure out why my experiment is inaccurate....


