Wow your water is so clear! I used cheap soil that was mostly woodchips and the water is heavy with tannins. It'll fill in nicely, especially when you get a little emergent growth it'll grow horizontally and reach down.
A couple of hardy fish or some RCS will probably help with plant growth, fert and CO2.
Raccoon eat aquatic plants? Are you thinking of moving it inside/screen room when it gets colder?