ok, this is what I do in my cov 16. Clean it thoroughly with dettox, then switch it on overnight (without water), and check the temp is 101/102 Then I fill the smaller, inner circle iin the base, with tap water, and put my mini humidity thingy in where the eggs will go. Checkin humidity is good...CONSISTENT is more important than actual number, around about 55% The incie needs to be away from window/radiator etc, in a fairly consistant room.
My eggs (if through the post, must settle at room temperature for 12-24hours) are selected. I do not wash eggs, I just select the clean ones, and keep the nestboxes as clean as i can). The eggs must be consistant for the breed standard, the right colour, size and SHAPE. When storing my hatching eggs, I keep them in my utility room, which is the coolest part of my house, and is temp and humidity consistent, and i turn them every 12 hours to prevent the yolk from sticking to the shell. Ideally, I use the eggs up to 7 days after lay, as viability decreases sharply after that, to close to zero at 21days old.
I choose the eggs i wish to set, and place them in my d.room (where I keep my incies). Once my eggs have reached room temperature, i mark each with a circle (and a cross on the oposite side) and lay them gently in the incubator. I turn all the eggs from the 'circle' to the 'cross', in a clockwise direction around 8am EVERY morning, then anticlockwise back again 12 hours later at around 8pm.
I have a high intensity candler, which I find can show up the telltale veins in an egg without me having to lift the eggs out. At 7 days, OH holds thlid up for me, while I hold the candler briefly(so as not to overheat them) over each egg. I remove clear eggs, recandling more thoroughly
just to make sure. At this 7 day point, I top up the water bowl in the base.
I dont open the lid at all then until day 18. Very swift recandle, if the egg appears black inside, good, if pale, clear or small dark blob, remove them (recandle if unsure). To raise the humidty to around 65%for hatching, the second/outer ring needs to have water in, and I put a hatching mat under the eggs (helps prevent spraddle legs). Then I call a "lockdown" no turning or lifting the lid AT ALL from day 18. I expect them to start signs of rocking, peeping and pipping day 20, and hatch day 21. if the hatch is early, incie running a bit warm, if hatch late, usually the opposite. Keep chicks in to fluffy up, for up to 24 hours.
Hope that helps