Well, I got everything up and running but I'm not sure if I have a problem or not so I need some more help. After getting everything put together I kicked off a backwash and after it finished I was getting some hissing coming from where the brine tube attaches to the valve. No leaks but it was making a bubbling and hissing noise and I could see occasional air bubbles making their way down to the brine tank. Not knowing what to do I went in to the house and opened up all faucets tubs and showers to see if there was still any air in the system. Doing this made it better but it still makes a very faint hissing nose and if you stand there long enough you can still see occasional drops of water escaping from the valve. Is this normal? If not, any ideas what I should check out?