Quote Originally Posted by chem geek View Post
Point 1: See the Are Borates Safe? thread for more details. The EPA limit for Borates is around 50 ppm due to the dog studies, a margin of error (MOE) of 100 and presumed small amounts of ingested pool water. It's all very conservative, but maximum label dosings would be no more than 50 ppm these days.
As a point of interest Bioguard recommends 30 to 50 ppm of Optimizer for halogen sanitized pools and 50-80 ppm for biguanide santized pools (probably for the algaestatic action of borate).
Then again, we used to use simazine as an algaecide in pools until it was banned. I am sure Ben is familiar with it.