Innokin makes some good products. Knowing specifically what you have as far as the mod (battery) or tank would help. I can tell you this though. Most people who move from starter kits to sub ohm vape cut the nicotine content of the e juice in half or more.
The rule of thumb is "the better the delivery device the more juice consumed and therefore more nicotine ingested." Too much nicotine can make you ill.
Search Results for Query: nicotine sick | E-Cigarette Forum Dizzy, stomach sick, headaches are some of the symptoms. From what I've read in the forum most people who sub ohm do so at 6 mg or lower e juice. Sub ohm tanks consume much more juice than the iClear 16 you've been using, a lot more. If you have juice, you can always buy the same flavor in a zero nic content and mix the two equally together, cutting the final mixture of nicotine in half. (for example 30 ml of 12 mg juice + 30 ml of zero nic , mixed together will yield 60 ml of 6 mg juice.
Not knowing what kind of power you are using it's difficult to advise. But there is another rule of thumb for vape : The rule for ANY vape device is the same. Start with low power, take a draw and add more power (wattage/voltage), then take another draw. Repeat as necessary. If your vape gets too warm, tastes funny, or starts to taste burnt, back it down.
If you can find markings on the mod or tank, or even a picture of it I am certain someone like the others above me could help you exactly with what you have.