Purchased my second ViVi today, unwound the wicks on a 2.4 which measured at 2.5 filled it, let it sit for 20 minutes and have had no issues so far. The juice I am using is a 50/50 on the second tank and the flavor was muted to start with. I put the same juice in a boge 2.4 and the tank has more flavor. So far I am loving these, as soon as I get the rebuilding of the atty down I plan on getting some new wicks and going to town on this unit. I am not a modder but I like the design so much I am willing to learn. 