Filtration System

• Although filtration typically isn't the culprit for green water, a failing or insufficient filtration system could allow oils, grease and algae to build up and decrease water quality. The CDC notes that a properly installed filter of the right size will remove contaminants as intended.
  
  

PH Levels

• The North Carolina Department of Environment and Natural Resources explains that a pool's pH level should remain neutral -- between 7.4 and 7.6 -- to prevent eye irritation, algae growth and damage to the pool's infrastructure. Following the instructions for your pool's disinfecting and sanitizing agent will ensure that you're adding the appropriate amount for the volume of water your pool can hold. Scrubbing your pool during this process helps prevent future imbalances.
  
  

Shock Treatment

• HealthyPools.org explains that a "shock treatment" adds a large dose of oxidizing chemicals to pool water to eliminate organic contaminants, such as disinfection byproducts, and human contaminants like body oils, lotions, perspiration and urine. Depending on use, shocking your pool weekly or after a large gathering helps maintain water quality and color.
  
  

Alternative Solutions

• A pool repair specialist can perform a home visit, and might recommend changing your filtration system, switching disinfecting/sanitizing chemicals, or draining and acid-washing your pool. A 10 to 20 percent muriatic solution, an acid wash involves scrubbing all surfaces with a non-metal brush. The Arkansas Department of Health cautions that such treatment requires a gas mask/respirator, rubber gloves, boots and goggles to minimize chemical exposure.