How to Treat and Prevent Black Algae


WHAT IS IT?

Black algae is a persistent, dark-coloured growth that can take hold in swimming pools, typically appearing as small, raised black or dark-green spots on the floor or walls. Black algae grow “roots” that dig deep into porous surfaces like plaster and grout making it the most difficult type of pool growth to get rid of.

POSSIBLE CAUSE

  • Incorrect pH level
  • Insufficient chlorine
  • Filtration/circulation problem


HOW TO TREAT BLACK ALGAE

1. Test and Adjust

Black Algae in your Pool?

Always begin by testing your pool water. Your test results will tell you if your water parameters are unbalanced. Your pH must be between 7.2 and 7.6. for chlorine to work effectively.

2. Clean Filter, Pool Water and Surfaces

Backwash and rinse the filter, skim water surface to remove visible debris, brush walls, vacuum and empty skimmer baskets. Concentrate on areas with visible dirt and little or no circulation.

3. Apply a Shock Treatment

Shocking your pool water helps to remove contaminants that may cause algae to grow and helps to improve water filtration.
Add 100g – 200g Month Mate Granular Xtra Blue per 10 000L or 1-2 Bags Month Mate Shock Xtra Blue per 50 000L (For heavily infested pools use the higher dose)

4. Apply an Algaecide

Ensure you select an algaecide that kills black algae. After treatment, some dead algae may remain in your pool. Continue to thoroughly brush your pool’s surfaces often.
Add 1L Month Mate All-In-One Algaecide per 50 000L to the pool as directed.

5. Circulate and Filter the Water

Run your pump and filter until the water clears, backwash and rinse the filter as needed. The longer the water is in motion, the quicker the water clears!
To help the filter trap the dead algae use 2 x Brite-Blu Clarifier Tablet or 50ml Water Clarifier per 10 000L after every backwash.

6. Chemical Cleaning the Filter

The algae spores stick to the sand which a normal backwash cannot detach and flush out. Use 1L Filter Cleaner per 3 bag sand filter to dissolves the oils, scale, and organic biofilms that stick to the sand.

SIX STEPS TO PREVENT ALGAE GROWTH

1. For best results, test and balance your pool water weekly, maintain pH between 7.2 – 7.6
2. Maintain a consistent chlorine level of 1–3 ppm, apply the Month Mate Super Plus Floater
3. Use a preventative algaecide like Tru Blu, monthly, apply 2L per 50 000L.
4. Shock routinely, apply Month Mate Shock Xtra Blue, 1 bag per 50 000L once a week.
5. Make sure there is adequate circulation and filtration, run the pump and filter for a minimum of 8-10 hours per day in summer and 6-8 hours per day in winter.
6. Brushing the surfaces is vital, brush the walls, floor and stairs weekly.