Yup exactly If you are doing a 1:1 ratio and diffuser then you are defeating the purpose of the diffuser. Also humidity in an incubator means nothing. You only care about what is in the tub. 1:1 weight ratio or more with a diffuser and a sealed tub will give you the right humidity you need. You may have to add water later if the eggs start deflating early. I don't ever measure humidity I just look at the eggs.