Soil for Wheatgrass?

I'm not sure which soil to use and how much to use with each tray of Wheatgrass.

Should I use the EKO Organic Potting Soil Mix with Azomite or should I use Genesis Wheatgrass Soil?

Also, shipping the Genesis soil is going to be pretty expensive and I'd like to know if it's worth the extra cost.

I can have 40 quarts (two bags) of the Genesis soil shipped for $31.93.
I can have 40 quarts (five bags) of the EKO soil shipped for $14.69.

So as you can see, it's going to cost me about twice as much if I want to use the Genesis soil. Is it worth it?

Also, how much soil should I be using with each tray? I've grown five trays so far and I used about 1 inch.

Any help would be much appreciated.

BTW, I don't want to make my own soil so that's not an option for me. Tweet