How to lower humidity in Virginia


In the Brooder
9 Years
Aug 15, 2010
I had a hatch on 10/3 that produced 3 healthy out of 38 eggs:hit. Eggtopsy seemed to show that the relative humidity was a little too high --- it was at 62% all along until raising it at lockdown. I've read that it should be between 58-60. Of everything I've read this is the most likely way I failed on all these little cuties...they were perfectly formed and ready, but there was not a big enough air sac.

Of course I said to myself, I can't go through burying all those little dead bodies again...and of course I now have 3 dozen more eggs on the way.
Assorted silkie bantams, mille fleur bantams, and assorted bantam breeds.

I'm using a GQF 1588 HavaBator. How can I lessen the surface area in the water troughs? My husband is suggesting little plastic caps such as from the top of gallon milk jugs.

Anyone out there with ideas on what to do....or who lives in an area like mine where the ambient humidity is more than what the eggs can withstand? How can I lower the humidity
Good idea. No I haven't and I will do that.
I'm getting the incubator all set up and ready, and tested, before my egglets arrive probably the end of the week.
I've got the 1588. The instructions say to only add water to one specific trough during incubation, then add water to another specific trough for lockdown. I do this and usually have humidity in the low to mid-40's during incubation and in the mid-60's for lockdown. Once they start hatching, humidity jumps into the upper 70's or the 80's. This has worked pretty well for me. Sounds to me like you are maybe filling more than one reservoir during incubation. Genesis TUV.pdf

Humidity is controlled by surface area of the water. Water depth does not matter. If you are only using one reservoir and getting humidity that high, I suggest covering part of the reservoir to reduce surface area, maybe with aluminum foil, maybe using plastic, maybe duct tape. Those plastic milk jug tops would work too if you float them on there and keep them dry.
Last edited:
try to see what your humidity is with the bator empty anywhere between 35-55% should be fine & take it on up to about 65-75% on day 18 & dont open it till they are hatched, i dont run much water in mine the first 18 days, if any at all, just depends on the % of the humidity.
Thanks so much Ridgerunner. I'm guessing your outside humidity is not too awfully different that ours. This incubator seems to run 1/2 degree high which we've discussed with the manufacturer, but that lowers the relative humidity. We even bought a hygrometer for this last hatch.

September here was extremely hot and humid. Maybe it's best to try to hatch in late spring/early (but not hot) fall.........

Just thinking out loud. Again, thank you for responding. If this one goes badly I truly don't know if I have the fortitude --- all those sweet little chickies and I'm just falling in love with the silkies. I had really good success with hatching out my own lakkies, but these shipped ones are a whole different ball game.
It IS confusing on these sites where people talk back and forth about humidity --- is it straight-out humidity or relative? Sometimes not sure.....
S-o-o-oo much to learn..........
I just use my hygrometer to tell me when I need to add water. I haven't even bothered to calibrate it yet. As you probably know, it can be way off in its readings. I just tried it the first time the way GQF recommended it and it worked, so I didn't worry about it after that.

Mine also runs a little hot. I've tried turning it down and it did not help. My hatch still started a could of days early. Oh, well. I'll try again next spring.

It has to be relative humidity, how much moisture is in the air at that temperature. It's the only way that makes sense.

I agree with Rebel for you to try different things before the eggs arrive and see where it stabilizes.

I don't have a lot of faith in all of us needing the same humidity to get good hatches. I think there are variables in there so that different people need different humidities. I can't explain the wide variety of humidities that different people use and have success, while someone else uses exactly the same humidity and has a disaster. I don't know what those variables are. I think some might depend on our height above sea level which gives different air pressure. Some people have suggested that the hens compensate for local conditions when they lay eggs by varying the porosity of the egg shell, but I really don't believe that one. How they are stored and for how long before they go into the incubator may play a part. As I said, I don't know what causes the differences. I think the best way to do it is to try something, eggtopsy the unhatched eggs, and make adjustments.
I am real close to Va. Beach I am using an older model HB a 1602 there are many compartments on my water tray I got the reptile model the smallest part of the tray was all I needed ful for september the R.H has gone way down the last week we have been at 35-40% . I am mostly hatching quail I have been runnig 55-65 percent with about half of the tray filled when I want a little more I fill the rest of the tray I hatch in egg crates the eggs stay upright during hatching the few chickens ( silkies E.E. and a few RIR ) that I hatched I did the same way.

New posts New threads Active threads

Top Bottom