The problem with the instruction manuals is they don't take into consideration a number of factors that affect humidity. I incubate at 30% for the first 17 days. If it doesn't stay 30% (at least above 25%) completely dry I add a wet sponge and it usually holds it right about 30%. My pullet hatch I actually ran lower than that a couple days because I felt the air cells were still a bit bigger than I wnted to see. The styro bators especially seem to do much better with a low humidity incubation.I have two of those incubators. I am by no means an expert, I have only done a few hatches (one current) and have not had amazing hatch rates. Having said that, I am confident that humidity has not been a problem for me and I have not followed the numbers in the leaflet. I have found that humidity is either low (under twenty) siting around 25 or over 65, if it is around 25, I leave it be, under 20 and I add a little bit of water, I monitor the aircell size and start to increase the humidity towards lockdown as the aircells are getting larger. The humidity figures in the leaflet seem to be counter to all other opinions I have encountered.
Do you do shipped eggs or local?
Did you keep the humidity high for your first hatch? If it works for you, don't change it.
If you find something that works for you and you are happy with the results, stay with it. Don't worry about what other people think.Well I did have it high but the air spells never got bigger they apwere always small