How can I Remove Green Pool Algae from swimming pool and spa? - Do you have a green swamp in your backyard? If so, you've come to the right place! Going out to your backyard paradise and looking at green algae infested swimming pool or spa is a horrible feeling. Usually this problem is either caused by a filtration problem, not enough sanitizer, or high phosphates. So how do you remove green algae from your swimming pool or spa? As you read further you will find the steps and products needed in order to solve this problem.