Green algae may have a fancy name, Cyanobacteria. But it’s certainly not a fancy companion in your pool. However, it does have its purpose, at least, outside your pool water. It occurs naturally, and is contained in nearly all soil and plant debris.

Those natural origins mean, unfortunately, that algae are always in your pool, and can colonise it when conditions are right. These include:

• • Poor water circulation, like low flow or dead spots in the pool.
  • Poor water balance, including pH, Alkalinity, Calcium and Cyanuric levels.
  • Poor water sanitation, like low or inconsistent chlorine levels.
  • Poor water filtration, such as short filter run times or an ineffective filter.

Any combination of the above can allow algae to take a foothold. Use a high-quality pool algaecide regularly as this will prevent the problems that cause circulation, filtration, or sanitation to drop below critical levels.

So how do you kill green algae?

The best way to prevent algae in pools is maintaining consistent chlorine levels of 2-4 ppm, with long, effective daily filter runs, good water balance, and weekly use of a good pool algaecide.

In other words, make your pool hostile terrain for algae!