humidity for ootheca trouble

[Mystymantis]

So this is my first time incubating an ootheca and I am having a lot of trouble keeping the humidity up. I have the ootheca in a 32 oz deli cup which is then inside a small glass tank with a heating cable underneath. Inside the deli cup I have some coconut fiber, also the bottom of the glass tank is lined with coconut fiber too. But the humidity keeps dropping to really low levels of like 30% even though I spray the coconut fiber once a day. And the coconut fiber keeps drying up super fast.

What other substrates or things can I use to keep humidity up since the coconut fiber seems to not be working. I originally had just a paper towel in the deli cup but that didn't work too well it kept drying up way too fast too. Or maybe I just need to put more water in the coconut fiber? but I don't want to put too much because then the humidity jumps to way too high!

So this is a dilemma. How do people usually keep humidity up or at acceptable levels when incubating ootheca? I am worried the ootheca has already been too dry. Will it still hatch if it is too dry for short periods?

 

[Serle]

I incubate in a container with paper towel on the bottom and a water container , beside my ceramic heater .  

 

[Nanodot]

Coconut fiber is too open to hold the moisture, I think.  I use Eco-earth (which is also coconut, ground up onto soil) and it holds a lot more water.   I put 1-2 inches in the container and I spray it whenever the top starts getting lighter brown.  My humidity is stable for a few days at at time,  even at 100 F.  

 

[Mystymantis]

Ok, thanks @Nanodot. Maybe I didn't have enough coconut fiber in the container, so I added more and it seems to be holding humidity better, at least at the moment.