If your CL levels are good... that's great
The most important thing when you water is cloudy (other than CL) is to make sure the pump and filter are working 24/7 until the water is clear. No chemical will remove cloudy debris and rusty or red dirt, only the filter. Let you pressures rise to 25% over your clean pressure. If 10 PSI is clean, let it rise to 12 or13 before doing a backwash. In a sand filter, it is helpful to let your filter get "a little dirty" to improve performance. DE can be added but it will require more attention but may make the process faster if you dedicate your time to it. See Pool School for more about this.