Basic greywater question

I'm installing my first laundry-to-landscape system and already have a dilemma.  

The washer being on an interior wall means I'll have to to through the floor and crawl space.  The greywater will travel a few feet uphill from the ground level before discharge into the landscape (but will never get up to the height of the washer pump).   The combination of these two things leaves me wondering if I should (option 1) put my vent stack inside just after the diverter valve, or (option 2) outside just after exiting the house.  

All the literature makes it seem like the pipe exiting the diverter valve needs to stay level before reaching the vent stack, in which case option 2 is out.   Since there is an uphill portion to the outdoor run some greywater will get trapped in the line between loads and stinky gasses might escape the vent if I put it in the laundry room as in option 1.  

Any suggestions appreciated.  

I can see why people would think a horizontal run would work like the sealing action of a trap, but it does not work that way, they just do not work. You have to run your drain pipe to daylight. You might have to dig down until you can place your pipe on landscape, but it has to drain. It cannot go up hill.

Travis Johnson wrote:I can see why people would think a horizontal run would work like the sealing action of a trap, but it does not work that way, they just do not work. You have to run your drain pipe to daylight. You might have to dig down until you can place your pipe on landscape, but it has to drain. It cannot go up hill.

What do you think will happen if I run it up hill?   Everything I've read just says don't go up more than five feet.   I'm only going up about two feet.  

Another dilemma: the folks at the greywater supply shop mentioned that once in a while there's a washer hose with an odd diameter that just doesn't quite adapt to the 1" barbed fitting coming from the diverter.   Well turns out this machine is just such a beast.   I guess I could try a 3/4" barbed with a hose clamp or 2 but I don't want to restrict the flow and put more pressure on the pump.  They don't really make 7/8" barbed fittings.   Any idea how people deal with this?

At the lowest point in the system put a weep/leak hole in the pipe. Just big enough so that their is no standing water in the system after say 3hrs.

Maybe a diy value that closes when there is a positive pressure coming from the washing machine but then opens after that pressure goes away.

You'll have greywater sitting in the portion of the pipe that sits lower than the outflow and the washer pump. Greywater turns to black very quickly, as in less than 12 hours and only 3-4 in warm climates. You really don't want a pipe full of this stuff anywhere near your living or food growing space. Like Travis said, the pipe has to go to daylight at or below the elevation of the pump outlet.