Algae stains often present themselves as black spots in your swimming pool. You may try to clean them up only to find them reappearing continuously. Signs you have black spot algae stains:
- The spots spread and multiply over time
- You see individual black spots on the pool surface
- The appearance of raised black spots on pool surface
- Algae spots only slightly improve with chlorine shock
Environmental factors that encourage the growth of black spot algae:
- Lack of chlorine shock
- Lots of foliage near the pool
- Constantly low chlorine levels
- Constantly high pH levels
- Very high phosphate levels
- Old pool interiors, in poor shape
It is not recommended to use acid wash to remove black spot algae because the algae lives in your filter, pump, and piping. The algae will just work it’s way back into your pool if your only source of cleaning is an acid wash.
If you are struggling with pool algae, you’re not alone! This is one of the most frequent issues pool owners face. The BEST way to eliminate algae for good is to remove the factors in the environment that are allowing the algae to grow. Once you remove the algae from your pool it’s best to have proper chlorine management to prevent a re-occurrence.
Warning: if black spots are left for longer than 2-3 years, the algae roots can absorb so deeply into the concrete pool it will be discolored permanently.