This is a styrofoam bator? Much discussion has been made on humidity levels throughout the entire hatch cycle,,my eggs went in this afternoon,and I have the humidity set on 45%,,it will stay this way until the last 5 days or so,then it will go up to 60% The true method is to weigh each egg before it goes into the bator,then re-weigh it several times while being incubated,,ideal scenerio,is the egg should lose between 10-12% of it's starting weight,,4% every 7 days.I have used these styrofoam incubators just as a stand by for when the eggs start to pip,but will never trust them to eggs costing $75 a dozen,,less shipping.or more such as with Coronation Sussex going for over $200 The temp flucuations are endless,especially when your room temprature changes such as when a door is opened and it's cold outside,or you turn the central air conditioning on in the summertime.You should get a temp-humidity probe with the sensor on the end of a cord and put inside the incubator about the top of the eggs level,to get a very accurate measurement of both readings. You can vary the humidity levels by adding sponges to the water depression,more or less water,and using a small fan,and adjusting the holes,open or closed more.Tape will work fine,so will and old carved cork from a wine bottle.If your temps are only fluctuating .5 of a degree,,leave the setting where it is,,and lockdown is a term used for the last 3 days eggs are due to hatch,,keep the lid closed,,so the humidity levels stays high,,constantly opening the lid will let this level drop off very fast.