Are you priming them first very well for about 10 mins or so? I have the Vaporesso Pro with a EUC 0.3Ohm coil and have used it for well over a year and the EUC coils since they came out about 6 months or so ago or whatever and I'm easily getting 2-3 weeks from ONE coil....literally, ZERO exaggeration whatsoever. I plug in the coil, drip a single drop down the center just to wet the inside a TINY bit then fill the tank and take about 5-10 dry hits and then a couple fired hits on about 20W only a couple hits, then let it sit a few mins, take a few dry hits then a couple more fired ones on say about 23W and I do that about 4 times over the course of about 10 mins then once I'm at about 25-27W I can set it to 25-30W (they do vary a tiny bit and the juice can need a lower or higher firing wattage) but then it's good to go and I don't have to touch it for a couple weeks...as soon as I need to start turning up wattage to get a good hit I now it's time to either change coils or clean my coils by cranking the wattage WAY up to about 300 or so on say SS mode and dry fire it for 1-3 seconds and then it cool WAAAY down, then do it again and repeat about 10 times but don't fire too long and don't hold too long or you will pop it.....once I do this I juice it back up like mentioned up top and I can get another awesome week or two out of it before I finally just change it. That's the best way I've found to prime and clean them for maximum taste and longevity and been doing it for well over a year. You shouldn't be at your 9th coil for at least a couple months literally, and even that seems too soon. I go through 15 coils in about 4 months....maybe 4.5 as I get 3 weeks out of one if I prime it well and then clean it carefully to squeeze that extra week out of it. Give that a shot. I'm using a Vporesso Tank just the regular EUC one but the larger one not the rounded top cap one, and 0.3Ohm EUC ceramic and burning them at about 25-28W or 320-380 on the stainless setting and they last about the same either way. Good luck!