I have a vv battery with a kanger mini protank , aspire nautilus mini tank with 1.8 ohms coil and an evod tank with 2.2 ohms coils.i'm vaping the aspire mini at 4.2 - 5 volts ,it seems to wick just fine ,for the evod and mini protank i'm using 4.2 volts and 2.2 ohms coils .are these volts too high?am I inhaling formaldehyde?I'm using hangsen 70 30 e liquid .I'm worried and nervous.whats the temperature of my coils at these volts am I actually harming myself?whats the correct volts to vape these coils at?