Borax as Algestat

[63john]

I saw a 2007 post about Borax used as algestat in pool from pool owner "Dive in the water gr8" and wondered if other pool owners have used Borax in large quantity level (50 ppm) for control of green or other algae. ? He appeared to have success. thanks

 

[JoyfulNoise]

I saw a 2007 post about Borax used as algestat in pool from pool owner "Dive in the water gr8" and wondered if other pool owners have used Borax in large quantity level (50 ppm) for control of green or other algae. ? He appeared to have success. thanks

The algaestatic properties of borates is over-stated at 50ppm. Borates act more as an "inhibitor" than biocidal agent. In other words, the presence of boron in the water at 50ppm interferes with certain cellular processes going on inside the algae (likely inhibiting key enzymes that contain diol organic structures). By causing this interference, the algae is either slowed in it's replication or it's reproduction is stopped.

Borates only become truly algaestatic at concentrations above 100ppm (and really closer to 200ppm) which would make the water unhealthy to swim in for large mammals and humans. Above 100ppm, there could be chronic toxic effects on very small children (babies) and pets (dogs or cats) that might accidentally (or intentionally) ingest pool water.

See here Are Borates Safe to Use?