I just bought some vivi nova tanks (2.0 size tanks) from myfreedomsmokes and I don't think they carry the replacement heads anymore. the heads that came in my novas are 1.8 ohm heads...I'd like to buy more heads for the future, but I am wondering if I should buy some higher ohm heads? I was reading that the vivi nova 1.8 ohm heads are recommended for use on ce4 type batteries and the like. I read the 2.4 heads are more for using with larger variable volt/watt batteries. I am vaping with a volcano lavatube and I usually don't vape over 3.8 volts anyways, but do I need to go with replacement heads that are the 2.4 ohm or can I stick with these standard 1.8 ohm heads? I am still getting use to these new vivi nova tanks, and they seem to be vaping kinda harsh so I'm just wondering if the harshness/hotness is because I'm using a higher end device such as my lavatube? I have been dialing down the voltage lately to see if that helps but it's still kinda of a hot vape to me. I previously was vaping with kanger T3 tanks and those were not so hot/harsh a vape it seems. anyways if I need to buy replacement heads for my new vivi nova tanks...should I buy 1.8 ohms or buy the higher resistance of the 2.4 ohms heads? and where is a good place to get heads online? and I also did buy two other vivi nova tanks locally and those had the 2.4 ohm heads inside, and those are a smoother less hot vape...it seems.