Shock

• Pool owners use shock to clean cloudy pool water that is not clearing under a normal chlorine regimen. Pool water can become cloudy from heavy rainfall, over-usage or in extreme heat when chlorine becomes less effective. Shock is the primary remedy for an algae-ridden pool. In special scenarios, super shock products are sold that range from 15 to 20 percent stronger than normal shock. This can prove to be a more effective treatment if the pool has algae.
  
  

Algaecide

• Pool supply stores sell algaecide that is added directly to the surface of the pool. Algaecide can be used to treat algae but is even more effective in prevention. Many pool owners choose to include an algaecide product in their normal pool maintenance regimen. The algaecide sold is either a powder or liquid form that is added directly to the surface of the pool water. If algae is present, brush the sides of the pool as well because it tends to stick and grow to the pool liner near the surface of the water.
  
  

Can It Be Mixed?

• Many pool professionals believe that chemicals always should be added separately for them to be most effective. If you are shocking your pool as part of normal maintenance or if the water appears to be a little cloudy, then you should always shock the pool independently and run the filter for 24 hours without adding any other chemicals. If algaecide is present, Poolcenter.com suggests that you shock the pool first. After shocking the pool and letting the filter run for several hours you can then add algaecide and brush the pool free of any visible algae.
  
  

Pool Maintenance

• Pool owners should understand that the best prevention of algae and cloudy pool water is a dedicated maintenance plan. Keep your filter clean of dirt and debris, and backwash immediately when necessary. Add regular doses of chlorine as needed. Use test strips every other day to measure chemical levels and adjust as needed. Vacuuming also is another overlooked area of pool maintenance that is critical to keeping your pool water clean. Dirt and debris that settle on the pool bottom can facilitate algae growth and lead to cloudy pool water.