Humidity control for the Mooskubator

As written in my first blog post, I wanted to tackle the problem of frequent desiccation of my cultures. I put it off for some time, since I seem to be bad at finding the stuff I want for an affordable price online. I needed a humidifier which either started misting when it was powered or had a built-in humidistat. Both allow an easy way for automating humidity control. I tried finding such a device several times on amazon, but no luck. About a week ago, I asked a good friend of mine to find one for me, and he needed less than 15min for it. The device with humidistat arrived two days later and went straight into my Mooskubator and started misting. As you can see on the following picture, it is quite enthusiastic.

However, it seemed to stop working properly. The next day my hygrometers at the top and middle registered humidities in the 60-70% range, which was quite normal for the Mooskubator. The humidifier itself was stuck at +90% RH. I suspected the moist air from the bottom had trouble reaching the top. So, I went out to find a small ventilator, and I got one for 5 Euros at a local electronics chain. I "freed" it from its stand and put it above the humidifier. When both were running the mist was evenly distributed in the fridge. I waited for an hour while regularly checking the various thermometers and hygrometers. The temperatures started to match each other, the humidity started to sink, but the humidifier stayed at 91%. Now I suspected something was wrong with it, so I took it out and disassembled it. Well, it was basically soaking with water. The air intake was routed through a pan meant to hold essential oils, which had a sponge full of water. No surprise the hygrometer was “stuck” at such a high value. I rectified the issue by removing the pan and baseplate to improve ventilation. Some electrical tape protects the electrical bits, and lids made for perfect stand-offs. When put it back into the Mooskubator it started working like I wanted it to. Humidity dropped, it started misting until a set value was reached, then stopped. All fine right? No. How the fan was set up allowed water to drop through the ventilation slits onto the electrical parts. To rectify this, I first contemplated ways to reverse the airflow, so I could invert the fan. However, then the mist would get pushed through the motor compartment. I decided on botching blinds: using tape, lids and a kind of adhesive dough the slits were covered in a way still allowing air to pass through.

Now it's like I wanted it:

This seem to work. If got the setup running for two days, playing around with the setting of the humidifier. Problems now are an increased, but tolerable, noise level, the copious amount of space occupied by both devices and the botched nature of my fixes. A 3D printer would be handy for these jobs. Maybe I learn how to draw the necessary parts and get them printed by a shop.