Hi, We are sorry you experienced an issue with Spa Marvel. It is one of our most popular water care products. Discoloured and smelling water would not be caused by Spa Marvel itself but can be caused by a number of issues - i.e. contaminants in the hot tub, filtration cycles, lack of sanitiser, and incorrect water balance.
Initially, we would suggest:-
Clear filters with filter cleaner
Shock the hot tub water
Add a clarifier
Increase sanitiser level
Check water balance - make sure Total Alkalinity is 80-150ppm and pH 7.2
Allow water to circulate continuously for 24 and re-clean the filter
If you would like to contact us directly we can go through these with you. Alternatively, you can read about these on the Spa Marvel website https://spamarvel.com/frequently-asked-questions/
