I am absolutely loving this new Ova Easy 100...I did 11 settings last year, and my results varied wildly. I decided my problems were largely due to egg weight loss (aka proper relative humidity maintenance). Lose too much and you end up with late deaths, too little early deaths...so for this first hatch I decided I was going to monitor my egg weight loss daily. This bator makes that task so easy its ridiculous.
I simply weighed each tray empty, then each tray full of eggs, at the onset. Then, at noon each day, I re-weigh each tray. A simple little spreadsheet tells me real weight loss, which I compare to an "ideal" weight loss (I chose 14% over 21 days as my "ideal" for this hatch, the number is highly debatable).
After 24 hours "ideal" weight loss is 38g, I'd lost 48g...so I increased the RH.
After 48 hours "ideal" weight loss is 76g, I'd lost 84g...so I increased the RH. Notice how the difference has gotten smaller.
After 72 hours "ideal" weight loss is 114g, I'd lost 118g...pretty close to spot on, so I've decided to leave the RH alone for a day.
Takes me 30 seconds to weigh the two trays, so the bator isn't opened for long, and recovery is really quick with this puppy.
In the past, I would have weighed on Day 7, so I would have run it at 35% until then likely causing far too much early weight loss. FWIW, I'm now running at 52% RH.