John,

10 Gallons is probably a bit small for D. Aratus. The recommendations in the past have been 5 gallons per frog but consensus seems to be moving towards a bit more space as a standard. I would recommend a 20 gallon if you can swing it. Also with a 10 gallon you really don't have much room with a background unless its very flat and with the addition of a water feature your really limiting your available space for the frogs to move around.