Day 18 of incubation, how low can I lower humidity?

[Alaskaduck]

Of the 11 eggs I received from Metzer Farms (they shipped to Alaska) 1 was infertile and 2 showed signs of a blood ring early on. I'm on day 18 with the remaining 8. I kept RH at 45% for the first 13 days. Weight loss wasn't within the 13-15% for ducks so I decreased humidity to 35% for the last 6 days.

Today, at day 18, weight loss is still under ideal. Eggs have been losing an average of 2.7g/day when to be at 13-15% loss, they should be losing closer to 3.4g/day. These numbers are based on a start weight (for 8 eggs) of 600g.

To catch up the loss over the remaining 7-10 days, I need to lower humidity to 20-25% (I think).

My question is, is this low level too low for the last week? Will they lose weight in a harmful or undesirable way?

 

[chickens really]

I never weigh my eggs....Lowering the Humidity can cause them to shrink wrap in the eggs . What kind are they?

 

[Alaskaduck]

They're Welsh Harlequins

 

[chickens really]

They take 28 days to hatch...I'm pretty sure the air cells are what they should be.....
I keep humidity at 50% till lock down and up it to 60%.....
Day 18 is pretty early to be concerned....

 

[Alaskaduck]

I've been feeling like I'm playing catch up at day 18. Seems the only way to tell if settings have been good enough is weight loss and candling. It's very humid here, been raining since I set them. If they haven't lost enough weight, their air cells could be too small.

 

[chickens really]

Day 18 is early....Only drop down to 40 for two days and candle again....Then once things look good up it to 50%...I understand because I am hatching two incubators of Calls ...

 

[chickens really]

It's humid here too.....

 

[Alaskaduck]

thank you, it's nice to have others to bounce ideas off of. I've been worried because the drop I did from 45% to 35% raised the weight loss only about 1%. Which I did read a ballpark calculation that said for every 5% drop in humidity, you can expect about 1% in weight loss. We've done so well so far with all the variables of shipped eggs and like anyone, I really don't want to get to the end and have hatch problems be because of poor incubation practices. I feel pretty excited that 8 out of 11 seem viable so far.

 

[chickens really]

I am actually running my one incubator with no water and the humidity is at 48%.....Its harder to get things correct but is do able...Try lifting the top off to the side even for 15 minutes at a time ?..Remove some water?

 

[chickens really]

Take out the plugs if any?