adding it to the tank straight is doable however you will be mixing flavors at that point so unless you don't mind mixing flavors even the slightest I wouldn't suggest it. I also suggest changing coils if your keen on single flavored juices am assuming you have a tank that uses pre made coils and not an rda/rta type atomizer.
other then that just got for it I always do this on my rda/rta it doesn't bother me imo the flavor changes very quickly after it gets vaped for a while with the new juice and then you don't notice the mixture. if I change flavors often though then it just gets ruined the flavor is so horrible after going through various different flavors. this is one reason why I suggest an rta/rda just take it apart wash it and dry and rewick. very simple process.
other then that just got for it I always do this on my rda/rta it doesn't bother me imo the flavor changes very quickly after it gets vaped for a while with the new juice and then you don't notice the mixture. if I change flavors often though then it just gets ruined the flavor is so horrible after going through various different flavors. this is one reason why I suggest an rta/rda just take it apart wash it and dry and rewick. very simple process.