Good to know that it only takes that much to shoot the humidity up that far. I just hate to have to constantly open up the bator to add the water and mess the temp/humidity all up.
When i don't want to open up the bator I use a straw and stick it down the vent hole, then I put a little funnel on it and poor a little bit of water into the tray. That way I can leave the bator closed. I have a Genesis 1588 w/egg turner.