Your tanko (blank tank atty) is not wicking properly, this is causing you to burn juice and/or get dry hits. Sometimes you'll get a tanko that works like a dream, and does until it dies. But in my experience, more often you'll get a tanko that either wicks badly from the start, or does so soon after.
First, since you've already go the equipment, look at your blank tanks, are they punched correctly? If the chad is still left hanging, that may be the cause of your woes. Sometimes you have to take off the cap and remove it by hand. Also, you can try fiddling with the tanko wick. Sometimes that helps. Also, for some reason you can't always transfer old tanks, to a new tankomizer. Sometimes it works, sometimes it doesn't. Thick of that spike as like a unique finger print, if you didn't punch the tank with that particular spike, it might not fit perfectly on another and that can cause wicking problems (and leaking). Odd I know!
But to tell you the truth, I've never been impressed with the tanko system. It's just too unreliable. It was the system I started out with, and if I didn't have access to a forum to see that a lot of people had problems with them, I probably would have written off vaping. I switched to clearos and dripping, MUCH better.
Now some people have really good experiences with tankos, I wasn't one of them. A lot of people agree, some don't. I suppose it does come down to opinion.