Thanks guys for the compliments. The bowl is back home for a while while I move into a new position at work and get settled there. I will be able to take some much better shots now that I can take pics with a DSLR.
As far as the soil, the Miracle grow "Organic" potting soil, also called MGOPS does not have any additives that harm fauna. I believe it took people quite a bit of trial to find the right soil. Even still, the sand cap is essential in my opinion, not only to keep the soil down, but keep the organics from fouling the water. I have heard some people that have disturbed the lower layer and had some deaths. I have not had any issues myself and I have a larger tank with the same soil set up and the fish are doing great in that one just like the shrimp in these bowls.
Do you do any WC or anything? I have a 2g bowl that I have a betta/small sponge filter (cycled) that I want to pull and turn into a shrimp bowl. would that be safe? also I have hardscape in it from a established tank