A fluid mixer includes a flow splitter and a mixing chamber. The flow splitter includes an inlet for receiving a flow of fluid and is configured to split the flow of fluid into first and second fluid streams. The second fluid stream has a higher density than the first fluid stream. The mixing chamber includes a first inlet, a second inlet and a mixing well. The second inlet is positioned below the first inlet. The second inlet of the mixing chamber is configured to receive the first fluid stream and the first inlet of the mixing chamber is configured to receive the second fluid stream to promote mixing of the first and second streams in the mixing well.