So I have this terrarium I need to keep at at least %95 humidity. Problem is I also need to keep a good amount of air exchange going on. What's the best way to get the humidity to stay up?
I have an air pump putting air through an air stone in a mason jar. This is helping with humidity and oxygen but not much. I also have a humidifier putting some amount of humid air into the chamber from a whole in the bottom. I'm not too familiar with humidifiers but this one seems to not be working too well. I bought it second hand for $4. I guess you get what you pay for.
Will the addition of perlite help or should I just go buy a $50 terrarium humidifier?
You need an ultrasonic humidifier. You got one that works by using a fan and a sponge.
I had a terrarium at 90-95% humidity, and using an ultrasonic humidifier I actually had to filter the humidity input because it was sending too much water in to the box. You can make a simple filter to reduce the water/air ratio by just piping it through a glass jar first, where some of the water will collect.