How do I descale a Portable Air Conditioner?

Water to Air portable air conditioners require water in order to run at full power thus resulting in calcium build up which could be a problem.
Some unit may have a water softener filter to change (i.e. PACWE130) while others require to be descale (i.e. PACW130E).
If the unit need to be descale just fill descaler solution according to the manual into the water tank and let the unit run until the solution runs out.
If the unit require a new softener filter follow the direction on the manual how to remove and reinstall the filter.