Sorry if this is genuinely a foolish question, but liquid water? Ice?
OT: I run a GeekVape Aegis with a SMOK TFV9 tank, and a CCell ceramic core. I had some HHC/THC blends kicking around unterped, and I mixed them all together and ended up with this weirdass ratio of 53% HHC and 47% THC (both D9 isomers), and I prefer leaving mine unterped since it hits smoother. I sometimes operate it out of a SMOK Scar-18 battery instead of the Aegis, but either one works just fine for me. I've got some THC-B and THC-V to work into the tank at some point, but it's so perfect for me right now it's not anything I want to fuck with too much. This box mod is also consistently reported back to me as the most devastating way people have smoked weed, exceeding e-nails even. My fiance is able to body dabs that would send your average person to the emergency room, but this box mod does him mad dirty for some reason.