Cause:
Here you have to distinguish whether the water is dark green-matt or light green-glittery.

If it is light green-glittering:
This is the natural colour of the water. If you want the water to be blue-glistening, lower the pH to 7.0 and add a small amount of chlorine. (Chlorine turns water blue)

If the water is dark green-matt:
This is a sign of deposits in the pipes and/or insufficient disinfection.

Solution:
Adjust the pH of the water to 7.0. Increase the addition of UltraShock by 20 ml daily. Start with 50 ml per 1000 l. Increase the amount to 70 ml/1000 l the next day, 90 ml/1000 l the day after and so on. If you do not have clear water after a week, we strongly recommend carrying out an intensive basic cleaning of your whirlpool.