Misters do not "atomise" water. There are basically three types of systems, sprayers, foggers, and humidifiers. Sprayers just spray a fine mist of water droplets into the air. Some of those tiny droplets stay suspended and float around in the air for a while but this is not water vapour measured by humidity. Foggers do the same thing but they spray out an even finer mist, though it is still liquid water droplets suspended in air. Humidifiers use heat to produce steam. This creates both water vapour and fog/mist suspended in the air. Now the issue is that all three of these methods mean that your tortoise is breathing in a lot of liquid water droplets and aspiration is one of the biggest causes of RI. Using a spray bottle or a water jug to add water to the substrate does not add liquid water droplets to the air, it simply allows the moisture to evaporate into water vapour. Its the kind of thing your Tort might never get sick if your lucky, but it only takes once, similar to using sand in your substrate, or using straight sided water dishes. The system your using also means that your tort is wet a lot, this is not ideal and high humidity is not the same as being wet, its not that surprising that your seeing skin conditions if your tort is wet all the time. .
