Manganese is not a very common metal, but can occasionally pop up in pool water, especially where the pool has been filled from a well or other rural source. Manganese can discolour the water coffee-brown, rose, or even purple, and can also stain the sides and bottom the same colour.
To remove manganese from water:
Manganese does not respond to Pool Magnet as well as it does to either copper or iron, so the best method involves the physical removal from the water.
- If manganese has been tested positive but has not discoloured the water yet, slowly raise the sanitiser level in the pool. DO NOT SHOCK. When the sanitiser is raised, the manganese will oxidise and the water will turn coffee-brown due to the formation of manganese dioxide. If the water has already turned colour, skip this step.
- Use Power Floc according to label instructions as a flocculant. This will drop the oxidised manganese to the bottom so that it can be removed from the water.
- After the manganese has dropped to the bottom, vacuum the pool to waste.
- Apply 250 mL of Pool Magnet per 10,000 litres to prevent any other staining or discolouration from trace amounts of manganese.
To remove manganese stains from sides or bottom:
- Test for manganese in the water and treat as above for the metal in the water, pouring the required amount of Pool Magnet directly onto the stains. A piece of plastic pipe can help direct the Pool Magnet onto stains on the floor of the pool.
- As before, do not exceed the maximum dose of Pool Magnet of 750 mL per 10,000 litres at any one time.