Exactly that. I don't like the tank, the perspex shattered I got a replacement and when you try and fill the top and unscrew the mouthpiece it's a chew on and it ends up unscrewing whole tank so need to use teeth to get off. Not ideal and just want a tank that fits the unit that allows me to utilise the units ability. I need one that comes with a fair number of spare catomisers or that are easily obtainable on the www. I not into making my own etc just want one where when it needs changing I just take it out and replace.
Well I made 2 suggestions for tanks, look which one you like, maybe watch a YouTube or two and read up a bit on them.
There are so many tanks out there, my suggestions aren't the only ones, just happen to be popular which usually is for a reason.
The more people you ask, the more they will suggest.
For your wallet sake, if you can't make up your mind , it might be worth checking the prices for the replacement coils you will need to buy. So tanks have outrageously expensive coils which might come as a nasty surprise after buying the tank.
Final thought. Most of us have bought at least several tanks over time. Consider it learning money and almost unavoidable. Finding a good shop that allows you to test a tank might help. In the end , money is better spend on tanks than on cigs
Good luck