well I don't increase it that much BUT it matters what your climate is, elevation, humidity levels in the atmosphere, inside your home conditions! I do a dry incubate I don't add water unless the humidity goes lower than 25% then at hatch time I add water and get it in the 40's...that works here but may not for you...I would probably start with you incubator recommendation and get advise from people in your region....you need a hydrometer or two...the ones that come with the incubators are attached to the lids so they only gauge the humidity and temp from the highest point...my humidity run a whole 10% higher where the eggs sit than the built in ones show...I have an incubator that is sitting in a different area of the room that I have trouble regulating so I'll be moving it...so see you have figure out you personal situation