I first hand tighten to where I'm not able to anymore. Then I put a crescent wrench on it and give it a slight turn no more than 1/2''. I followed this method will all the parts that needs to be tighten other than the ASA On/Off valve itself. That can be hand tighten which will be fine.
This method, I used with my gauge also. You will need a decent size crescent wrench, since the Gauge itself is 1'' inch in diameter.
Please keep in mind if you over-tighten it already with a wrench and it leaks. Open it up and inspect the rubber black washer that goes inside the needle valve nut, before you go and try my method. If that rubber black washer is anyhow "damage" it will result in a defective unit.
Yeah, im not having any problems with leaking, just a floating valve, thats it.