Consistent humidity

starting my third grow and early on im running into external problems of sorts! My plants are in week 1 of total life, so first week as seedling, doing fine, plants broke tge surface and started developing small leaves and got small glasses on top as a greenhouse.
The problem im having is i cant keep the humidity consistant at 40% minimum. I have the same small humidifer as befor that attaches a water bottle and could not get it above 30%. I got another one with a small resivor and it helps but dries fast and humidity drops again.
The temp is consistant @ 72, i have two fans at the bottom moving air and one uptop to vent the air.
Last night i shut some of the vents because i figured more non humid air was coing in that humid air was being produced. It helped but still dropped over night with just one humidifer.
I cant lower the temp much more because its winter in pPA where i live and im already on the edge as far as tenp goes. So is there any other method or something i can do to get the humidity up and stay up without having two humidifers or getting a bigger more expensive one?!?
Any help is appreciated sorry for drawn out post

Don't dome them. Better to have low humidity than suffer damping off. If they are falling over, it may be too late.

Being Winter here also I was having the same problem with keeping the humidity up in my tent, I couldn’t get it above 38% at 77*. I placed a small tank type humidifier in the tent, $25.00 at Menards. You may want to try hanging some damp towels in your grow area. My plant are still young too, 2 at 16 days and 2 at 10 days. Temps stable in the 77* range with RH at 66-70%. The plants are loving it.