I currently have a 29 gallon tank for my FBT's, Its about 4/5's water, and 1/5 land. Theres shallow water though and then it drops off pretty steeply about 5-6" deep and most of the water is that deep.
But I have So much pothos in there that the roots fill much of the water area. I also have a filter in there that keeps a water current going. But I added duckweed to it, like a handful, so hopefully over time I'll have the water surface covered with it, it will look very nice I Hope. I have 4 Algea eating fish in there, thats why I have the filter keeping the water current going, so there not cut off from the oxygen.
I'll post pics as soon as it gets growing!
-----

www.mplionhearts.com