Well you have to find a method that works well for you, I got mine a week ago, and the first time I put a carto in I was very excited and anxious to use the phiniac, I shoved it in and mess up the oring, I kinda shredded it and got little bits of rubber floating around the tank. There is a great tutorial on youtube and on the phiniac site on how to do it right. Importantly you have to lube the end of the carto with some of your juice. You can also buy the little plastic tool they sell for helping with the insertion of the carto and protecting the orings. I works great, but hardly use it any more as the orings have softend . I found that attaching the carto with the tank on as far as it goes in , to my KGO battery helps me gently twist it in the rest of the way. Also attaching your drip tip on the top helps slip in also. Just be careful, because once it does slip in you can over push it and it might slip in to far and you will spill your juice. These tanks are very tight and wont slip once attached properly, so that being said, they can be a bit tricky when using them for the first time. Also be careful of thick juices as cartos are sometimes fussy and wont wick well. For me, I punch 2 holes on bottom close to connector one on close to the open part because I found it flows better with the top hole as an aeration hole. This helps because of the vacuum caused by the tight seal these tanks have. I had a few frustrations with the tank, and thought why did I get this and get myself into this mess? Once I did some research on you tube, and saw the tutorials on the phiniac site I found my way. Just relax, put it down. Maybe get a carto and drip , take a few puffs and relax. I love it now that I found my method. I also kept wasting juice when trying to fill it after the juice went down, so I found using a syringe helped A LOT. If you make the holes on bottom and the one on top it makes filling the tank a bit tricky as when you slip the carto down and try to make space some juice spills out of the holes. The needle is thin enough to fit into the space with out making a mess. Also when changing you carto, I use the method where you take the new carto, prefill it using the condom method, than I take the end that has the connection to battery and slip it onto the bottom end of the old carto, then you slip it right in and the other one slips right out, I found this on youtube also. I hope this helps , not make things worse. The phiniac tank is wonderful and I dont see myself being with out one. I had also bought a cheap smoke tech tank, though its not a bad tank, it doesnt have a good seal and the caps come off real easy and I spilled so much as the cap would come apart when I tried pulling the old carto off. The smoke tech works fine once it on and going, but it is slippery and can come off your battery or carto much easier. Just check on youtube and check the phiniac site. It helped me out a lot. You can do this. If I did it, anyone can.