helium argon mix

New to tig welding and have been reading about the benefits of using a mix of helium and argon for aluminum welding.
Two questions I have....
1. Can I get both argon and helium in one tank and use one reg instead of mixing from two tanks.
2. Is this mix of 50/50 also good for steel. I would not at this time get a second tank and buy an extra reg etc but if I could swap out my tank at the next refill for a 50/50 mix I would do that if it was still ok to use this mix on steel. If its no good for steel and or I can not get this mix in one tank I will hold off for now and put it on my maybe or wish list for down the road....thanks wayne
....enjoying my PM 205 very much. The switch over from oxy/ace to tig is very easy and love this little unit. If I can master Aluminum I will be very very happy.

Yes you can get helium and argon mix in the same tank,I use it at work often. I believe the mix is 75/25 argon / helium and we use praxair astar 75. It can be used on mild steel. We use it to tig sheetmetal guards for the machines we build. It seems to work well, but I would check with Everlast support to see if your machine can use argon helium mix. Hope this helps you.
Robert

Yes, it can...however, helium may make arc starting more difficult and require a resetting of the points.