regardless of what wire you use the aqua shouldn't get hot. its not the wire or resistance but another contributing factor . I have heard of aquas getting really hot and know for sure its not suppose to happen because I have an aqua and run it as low as .35 with no issues at all. I also received a clone and tried a build in there, also with no heat. if you tried it with kanthal and it got hot and then tried it with nichrome and it wasn't hot then we know there is no issues with airflow, (I have heard with certain clones of airflow issues). being that there is no issues with airflow it has to do with the build or wicking differences that were changed when you made a new coil. you mentioned nano build? have you had the same heat issues with just a micro build? so its just a nano build that heats up the aqua with kanthal? if the heating issues are with a nano build only maybe there is a reason or difference with nichrome, this I cannot comment on because that is about the only coil I have not tried in the aqua. but if your aqua gets really hot with a micro build on kanthal and not with nichrome, I can definitely tell you its not suppose to happen and is not the wire that is attributing.