Monitor with the right equipment
In order to have your flock at optimum environmental conditions you will need some additional equipment to help you, especially if you do not have a CE house. Even if the house environmental computer gives these stats. Ammonia meter, CO2 meter, hygrometer for % RH as well as a wind speed measurer in meters per second. In order to measure the % moisture in the litter one needs a unit somewhat like a hand held infrared thermometer (which you also need) and this can give you an instant reading for the surface moisture %, you will also need to remove litter to create an opening (a small gardening four-pronged fork) and take more readings of the litter below the surface. Wet litter is classed at +- 35-40% moisture. However, you should aim not to be above 20%. The old yardage of measurement to give a rough idea is to squeeze the litter in your hands and estimating, if litter clumps and stays in a ball, it is too wet. If litter instantly dissolves and falls in fine particles, it is too dry. If the litter initially clumps and then starts to disintegrate it is probably ok at 20-25% moisture.