What are the best settings to tig welding aluminum on DCEN?

Well  there is always a bit of fudge factor because flowmeters are different, and machines are different …but 210 amps, using a #5 cup and 20cfh of helium with a 2% lanthanated 3/32" (2.4mm) along with 1/16” (1.6mm) 4043 filler rod is what Roy used for this video.  

A foot pedal was used and as I was watching, I would guess that about 90% of pedal was used at 210 amps to get the puddle started, but after that Robin backed off a bit for the rest of the weld. So I would guess around 180-190 amps were actually used for most of the weld.