The soil I got was the Expert Gardener Potting Soil from Walmart.
I capped it with Safe T Sorb (fullers earth)
I tried to get the soil as close to 1" as possible, but some areas are shallower or deeper. However, I did try to get it as close as possible.
Here are some quick shots of what I experienced:
And heres an overview shot of the tank. I've since added a second dual t5 fixture: