I still think diffusers are the way to go. You may need three.
Vertex makes aerators designed for shallow water. A friend of mine had a fountain and it caused excessive evaporation. He had to take it out and replaced it with a diffuser.Other people may have had different experiences with fountains. I love my Vertex

"If people concentrated on the really important things in life, there'd be a shortage of fishing poles." Doug Larson