New tank owner...

[teknitroxdiver]

I don't think it should. But keep in mind that it is theoretically possible for trimix to stratify over time, although you probably won't be dealing with that.

 

[Ontario Diver]

Myself, I drain my tanks down to about 200-300 psi when I put them away for the winter. It is a little easier on the tanks and less of a risk. I have to drain them at the beginning of the year anyway for the visual inspection and valve work.

Any pressure above abient is good to keep water and fumes out.

 

[kherron]

Minimum pressure, from my understanding, is 20 to 50 psig.

Checked my Cylinder inspection manual just to be sure. You are correct the recommended storage pressure is 20psig.