I just found this website so thanks in advance to anyone who can help me here as I am at my wits end. I have a dual tank water softener and recently one of my tanks has started leaking at the junction of the threaded tank collar and where the valve sits on the tank. I've checked numerous times there is no water leaking from the tank itself or where the collar meets the tank but right where the valve sits. As soon as I put it into service and the pressure builds in the tank it starts too leak. water softener itself works fine as far as I can tell. I took the valve off and checked the large o-ring where the valve sits on the collar and its pliable soft, no cracks and maintains its shape. I have even tried wrapping the thread with thread seal tape with no luck. I am a newbie home owner and don't know much about plumbing, but I am pretty mechanically inclined so I am trying my hardest not to call someone in and charge me just to look at it. Any ideas or advice on where and why the leak is happening? Thanks again in advance for any help. Here is a pic, its leaking right at the top where the white collar meets black valve seat.