Humidity Question for Setting Eggs in my Incubator

Got my eggs today and will be putting them in the incubator tomorrow am. Question is about humidity:
My new Brinsea 40 is reading 48% humidity, will the humidity drop or rise when I put my eggs in. It is slowly dropping as I've had it on for 3 days now and it started at 57% and dropped to 51% the first day and since then has only dropped the 3% (incubator is set at 40%) Any help or advice would be much appreciated.
Thanks, Holly

Im going to guess that you need to vent it a bit more in order to get it down to the 40. (It can adjust itself up if you have a humidity module but cant go down if humidity in there is too high)
Not sure which way it will go when you add the eggs but in my opinion the TOTAL average humidity during the whole incubation is the thing to pay attention to, not daily fluctuations (unlike temp which you want to have nice and steady!)
I would say if temp is holding steady put those eggs in, wait 24 hours and then adjust the temp/humididity gradually if it is not where you want it to be.
I find Brinsea incubators are usually dead accurate for temperature and usually get great results...BEst of Luck!

It has been my experience that one should worry about humidity excessively. I know they make a point of playing up the crucial importance of humidity in the bator instructions, but really, they just can't emphasize it enough. In fact, my best hatch results have happened when I gave up sleeping for 21 days straight, stared at the bator for hours on end and muttered over and over, "I am really worried about that humidity." Let's face it, stupid things like hatch failures only happen to those brain dead dopes who don't worry enough! You have to exert some serious, emotional agony here. Concern bordering on hysteria, to truly begin to approach humidity competence. It's a big order.

In the unlikely event that you have not noticed, this is a sarcastic piece aimed at the people who write bator instructions...as if a device blowing hot air and shifting eggs in a little rolling shelf can ever hope to replace the perfection of skin-to-shell contact that a hen provides...puhleeeze! When you place eggs in a bator you have taken a step so far into the dark side that you may as well toss the instructions and make up your own as you go.

I do. It's funner that way.

When, after agonizing over humidty I had perfect chicks drown in their shells I decided to heck with this. I am a DRY HATCHER. Not a drop of water goes in. This idea strikes fear into the hearts of those who find security in their bator instructions. Pffft.

Use the 'search' function at the top of the page (next to Home and Calendar and FAQ) and see if you can dig up past posts on this topic. There should be lots of debate and something for you to think about...as you steam up your glasses over your oozing, humid bator. They're chickens, not alligators! Either way, good luck and have fun.

We have been using a brinsea 20 this past year, it is an awesome little machine, and I imagine your 40 is not much different. We decided to try no water in it and see how the incubation went, and it was awesome. Now I live in dry old Saskatchewan, humidity in my house is around 35% at the best of times, and I did just fine.
We did have trouble HATCHING with no humidity though, so I add water the final 3 days, I dont have a hygrometer so not sure what it bumps the humidity up to but they seem to hatch 90-100% with this method (of fertile eggs).
Duck eggs are different, not sure if you are talking chicken eggs or duck eggs. Duck eggs we mist daily, and put water in the trays the final 4 days.

Thank you all for your replies. I added my eggs this am and the incubator went up to 54% RH, that was at 10 am. I am leaving the vent wide open in hopes that it will bring the humidity down. At noon it had dropped 1%, so I will leave it open and am going to aim for 40% and will adjust from there. Next time I will try my own eggs with no humidity. Five days and I will find out how it's doing. I weighed 20 of the 48 eggs and will weigh again on day 5 when I candle. Excited and hoping I get at least a few out of the hatch. Late in the year but had to try as I wanted to check for warranty purposes. Just stuck my spot check in and was about to panic it went to 38.1 but is dropping now and is at 37.9, set at 37.5, reading 37.6. Should I lower it at couple of points to 37.4? I know you say wait but with the temp that high will it hurt the eggs? Tried to put pics on but don't know how. How long should I wait for the temp to go down. (Scared). First Incubation for me.

Okay I'm a slow learner, here are the pics

temp looks good, humidity seems high, do you have any water in there?
I only have experience with the 190 and the minis...

Yes I do and I had the pump hooked up, so I just unhooked the pump and will see if this brings the humidity down. New Incubator and first set for me. Learning curve. Thanks.

Unhooked the pump for about an hour and left the vent open all the way. Dropped to 33%, so hooked the pump back up, closed the vent completely and now two hours later I am sitting at 37.5 and 39% RH. Hope this is not a screwed up humidity reading. Have weighed eggs so will know if I'm close in a few days.

I realize I have left comments for you elsewhere on this topic but will leave comment here too for anyone else reading this.

Unhooking the humidity pump is not necessary. Just go into your Humidity settings on your Brinsea and lower your RH% by a point or two. Wait an hour and then check your reading.

Many people will tell you of the importance of not opening the incubator on Day 18 [lockdown] in that you don't want swings in either temp or humidity. However, the first 3 days of incubation are just as important for healthy embyronic developement. Set your temp and humidity and resist the urge to open the incubator up.
I would recommend any adjustments to temp or humidity just be made by suttle adjustments to your Brinsea settings, wait an hour, then recheck your readings.

One other thing is check to see no outside heat source is effecting your incubator, such as sunlight or heat register.

Well it is almost 9 here now and my relative humidity is holding steady at 39%, set to 40% and the temperature is holding steady at 37.5 on the machine and with the spot check it fluctuates between 37.4 -37.5. I do not open the incubator to put the spot check in but feed it through the vent hole. Right now the vent hole is closed and humidity is holding, so will leave it where it is for now. I did have to open the incubator briefly as one egg fell out of the cradle, no damage but didn't want it banging around in there breaking itself or other eggs. Had the incubator open for less than a minute. Now the incubator will stay the way it is until day 5 to 7. Thanks to everyone for all the advice.