im experimenting with refilling the cartos. so far it seems that the thinner the juice the better they work, my 510 taught me i need a fairly thick juice so it dosnt leak but they cartos get a fairly hard draw with thicker juice. My current mix is 80% pg, 20% vodka (could use distilled water) and it vapes great, no much vapor though, goto keep working away
I totally agree that the prefilled carts are just plain nasty, cigeasy sells empty ones, but i just get coffee or mint (the only 2 ive found that are vapable) and vape them out then rince and refill.
Getting the top off is easy, i use a dental tool, but a fork works great also. Just take it easy and slow, put fork in, pry a little, and turn, pry, turn. First time it will take a while but dont force it, it will work free. After the first time itll pop out real easy.