I peeled the black sticker off my carto, it comes off pretty easy. The carto won't flood if there are no air leaks. The first one I used, I wasn't very careful when I slid the needle down the side of the vinyl grommet to fill it and as a result, nicked the vinyl and my carto kept flooding. This second one, I have been very careful when refilling and have had no problems with flooding after 5 refills so far. I bought a 50pk of grommets at amazon to have replacements.
Earlier today I found some older vanilla juice and wondered what would happen if I dripped down into the carto that was in a tank full of juice. Big mistake. The carto flooded and it took me several times blowing it out and sliding my nail between the tank and grommet to equalize out the air pressure. After a few times blowing it out, the air pressure equaled out and all was well again.
I've read of people compaining about the carto not looking "wet" at the top but it's not supposed to. When you fill a tank with a new carto in it (empty) the juice will seep through the hole into the carto. As you vape, the juice will keep seeping into the carto, keeping it wet. I've noticed when I vape, tiny bubbles will slowly come out of the hole. I really love using tanks, I resisted for a long time because of the price (some are $25!) and the fact that I would have to punch holes in my cartos. (not hard to do)
The
chibi tank is only $8 and it comes with a prepunched carto already in it. That was cheap (and simple) enough for me to give it a try and I'm so glad I did! I can refill once a day instead of having to keep dripping into a carto. I don't have to worry about it getting dry cause I can see how much juice I have left.
As far a foul flavor, I haven't noticed any and I would imagine that depends on the juice you use. When I use tasty vapor juice in a carto (without a tank) it starts tasting a bit foul by the second day. I've been using KBV warm sugar cookie in the tank and same carto for several days and when I just refilled, I got the same fresh flavor. I've heard that cartos last longer in a tank but I haven't been using the tank longer enough to make that judgement.