A little background first. Or just skip the spoiler and see the build. I added Philosopher's Stone to the title, thanks to @M.C..
I now present Gaseous Element Converter 2.0
What makes this work?
The liquid valve supplies 70g/s of liquid (works with 50 and 60 as well, but not 100).
The tile to the right of the vent constantly swaps from water to vacuum. The 5 lower tiles should all have sufficient water to never swap to another element.
When the tile becomes