so i am brand new to rdas and i don’t know what watts I need to hit them at , my rda is comming in today and i have some prebuilt coils comming to (.36, .45 , .85 and .5 ) if I put two .5 ohm coils in does it make it 1 ohm or .25 ohms and how do I figure out what watts to hit them at or is there a calculator of some sort