How are you measuring the humidity? If you are using the built in instruments, they are notorious for being inaccurate. Suggest you purchase and use a standalone hygrometer or a combination thermometer/hygrometer.
New member from Oklahoma. 86 years old. Retired from the U.S. Air Force in 1978. Have been breeding poultry for well over 10 years. Presently have Buff Orpington, Black Australorp, some mixed and one old Icelandic rooster. I also have the 3 white varieties of turkeys: Midget White...
Liquid Corid is easier to use. The powder tends to cake. I routinely give all of my hatchlings Corid for a minimum of 7 days before they leave the brooder. In wet weather, I extend that to 16 days. I use 4 drops to a pint, 8 to a quart. Should be sole source of water.
