I'm sure this may have been discussed somewhere already on the forum but I thought I'd share my experiences 
After having my 2.2 Ohm Protank set to 4 volts for a few days, I stared to notice a decrease in my vaper production. So I decided I'd clean my tank and apply a dry burn technique to the existing wick and coil courtesy of watching this video
How to Clean & Dry Burn... Kanger ProTank - YouTube
What a difference this technique makes and only took me about 5 min. Now my Protank is back to vaping like it did the first time I put her on my Vamo.

After having my 2.2 Ohm Protank set to 4 volts for a few days, I stared to notice a decrease in my vaper production. So I decided I'd clean my tank and apply a dry burn technique to the existing wick and coil courtesy of watching this video
How to Clean & Dry Burn... Kanger ProTank - YouTube
What a difference this technique makes and only took me about 5 min. Now my Protank is back to vaping like it did the first time I put her on my Vamo.