So my plants are in veg and my humidity has gone to about 45%. I was looking at humidifiers today and the only ones where you could actually set the humidifier that a set humidity the other ones that I could afford had just a on and off button . How do you run them ones without the humidity going to 100
With a hygrometer in the room, but you would have to manually check the humidity and turn it on/off. Personally I wouldn't worry about that being too low of a humidity unless you are experiencing problems. You probably don't need one.
I live in a very low humidity area 20-30% on a wet day, i have not seen any issues once the plants start to really take off, young seedlings will drink more to compensate for lower rh so be careful with your nutes..
Your plants will be fine. I grow in way less humidity in the winter, sometimes in the teens. They drink more when it gets thst low. 45% isn't anything to stress about