"A model 6 huh? There's a blast from the past. Oceanic probably hasn't made that skimmer in over a decade. To bad too, they're not a bad little skimmer. As for the valve, I guess it depends on the pump you have. They were spec'ed with an Eheim 1250 which seemed to work very well. I ran the 1250 wide open and used an air valve on the venturi inlet to adjust the water hight. As the pump aged I ended up pulling the air valve off and running the venturi wide open. By the way, I used a fitting to thread the pump directly on to the input of the skimmer and all of it sat in my sump. There was no hose between the pump and the skimmer. I felt this was the most efficient way to run it.
If you can let it drain into the wet/dry I would do that. Putting any kind of fitting and hose on the outlet caused too much back pressure and made it very difficult to adjust consistently.
Maintenance is very simple too. Clean the cup and neck often for optimal skimming. Stick the end of the venturi air draw into a cup of very hot RO water about once a week. This will help keep it clog free between major cleanings. Every so often, take everything (pump and all) and give it a vinegar bath to clean out the calcium deposits and what not. That's about it."