The stability and performance of the gas suspension calciners at the Rio Tinto Yarwun Alumina Refinery have been severely impacted by variable and high feed hydrate moistures for many years. High calciner feed moisture creates instability, causing trips and high energy consumption. A study was completed to identify possible improvements which led to the identification of a suitable drainage aid and the commissioning of drainage aid dosing systems. Ongoing work has included operator training and standardising troubleshooting methods. This paper outlines the improvements achieved to date and the path forward for sustainability and further optimisation.