It's a list of all the people and things I hate so much I want to hit them in the face with a shovel.. Concept coming from the Marian Keyes novel, The Mystery of Mercy Close (2012).
Use chlorine as your go-to algae killer. When your pool water is green or contains visible algae clumps, your pool does not have enough chlorine. Shocking the pool with a large dose of chlorine is the most effective way to kill the existing algae and bring your pool back to sanitary conditions.
Once you get rid of the Mustard Algae (through various steps), this product is used once a week as a preventative. The way I understand it from my local pool people is that the algae lives off of the phosphates in your pool, Phosfree kills the phosphates, therefore the algae cannot live.