Both Liquid Scale Dissolver and Imperial Scale Remover (Season Start) contain a "pH color indicator" that will guide you through the process. When the acid/water cleaning solution is at proper strength, it will be green-to-light blue in color. When it is neutralized and unable to dissolve scale, it will be purple. When it turns purple, another dose of acid equal to the first must be added. The system is usually clean when you can maintain the green color for 20-30 minutes.
You should always be aware of any local regulations that may govern the disposal of acid cleaning solutions. However, in nearly all localities, it is acceptable to flush the solution to a sanitary sewer with water once the solution has been neutralized. The solution should be neutralized while it is still in the system, through the use of soda ash or similar alkaline neutralizer.
Either Liquid Scale Dissolver (a liquid hydrochloric or muriatic acid) or Imperial Scale Remover (a powdered sulfamic also known as Season Start) can be used. However, all acids will remove a small amount of galvanizing during cleaning, and the use of Imperial Scale Remover, or Season Start, is the best choice as its inhibitors will provide up to 96% protection of the galvanizing.
