No, it's just plain ol' sand so I'm thinking a bit of iron might help, especially the nesaea pedicellata. And yup, Excel is the one with carbon. There are a few other brands that make C02 supplements but I think Excel is the easiest to find and probably the most affordable.
Since I don't have live plants in the tank with that light, all I got was algae. I had to take the light off and put a plain ol' fluorescent bulb on and I'm still getting algae. I need shrimp for my sorority.