u can get mist systems 4 greenhouses but on a smaller scale they are expensive tho try searching DIY misters, i have an ultrasonic fogger it makes a super fine mist over the water , makes the tank quite humid, needs bout 5cm of water to work , also u need to hide them so critters dont walk over them a pile of large flat rocks would be ok, another thing is that they heat up the water really quick i donty know much bout newts but if they are sensitive to temp like axies i wouldnt reccomd it unless u have min 15l water in there, u can put it on a timer to come on 4 15mins every hr this way the temp doesnt rise too much