Do I need an internal coating on my lime slurry tank?

In general an internal lining is not required. Lime slurry is not corrosive and will in fact inhibit rust formation. However, if you intend to shut the system down frequently and flush with raw water, or perform a regular acid flush to remove scale from the tank you may want to consider a protective coating compatible with the water/or flushing fluid. Some customers also find that selecting a coating with a smooth finish can help limit build-up on the tank walls.