Im in dire need of some new heads for my protanks the 5 pack I bought sucks- and tainting all my juice. I have tried 3 new ones today. I seem to prefer a low resistance and these r 2.5 can't seem to get the voltage right. I think 2.2 would be good? I think its the SID mod I'm using. Can't wait to get my Provari. Hope it makes a difference!! Feeling frustrated I know people say RBA way to go but I just want to put things on and go. To much fidgeting for me? Where do you buy your heads from. Could they be duds or is 2.2 better?