By definition, the word automate means to operate by machines or computers, so reducing the amount of work done by humans. When applied to management of pool water chemistry, it means something every pool must have.
Before automation was introduced to the pool industry there was a trend of using high amounts of chlorine to sanitize. Why? Well the answer is actually quite simple. Because the methods of sanitizing were left to human error people felt that by using an excess amount of chlorine there would be less chance of having a dangerous situation.
Automated Controllers have changed this thinking by insuring a constant amount of chlorine (or other sanitizer) is fed at all times. By automatically controlling the amount of chlorine being used safe water can be maintained with lower levels of chlorine then ever before.