The humidty in my Little Giant was at 34% with one little bowl of water. So I added a second bowl... and now it says 27%. Um... what? Am I doing something wrong with my thermometer/hygrometer? Or is the humidity just that low with more water... even here in wet Washington?
I don’t know how good your hygrometer is or if you somehow repositioned it or did something different with it. That’s a real possibility. Did you give it time to stabilize after making changes? It can take a while especially if you let the humidity and heat out when it was open. If you spill water in there or get another surface wet, the humidity can spike until that wet surface dries off so had the humidity stabilized the first time you took the reading? Is the incubator located where a heating vent affects it? The temperature and humidity of the air going in affects the humidity of the air inside the incubator. It’s hard to know what is going on without being there, but if other conditions are the same you raise humidity by increasing water surface area. So some condition can’t be the same if you allowed it to stabilize and your instrument is close to accurate.
If you are trying to up your humidity add a couple wet sponges to the bator. It worked great for me and it was so much easier at hatch time to grab out a sponge, wet it and slip it back in w/o loosing my already established humidity. I did a dry incubation and upped it at day 18. Had a great hatch.