Water clarity issues typically stem from one of two causes: water imbalance or filtering problems.
Water Balance
When your pool is cloudy or green, first check to see that it is balanced properly, either by using your own testing kit or by bringing a sample to the store for analysis.
If any chemical level is low, add the recommended dose of the appropriate chemical, and run your filter until the pool clears.
Common causes:
1) Low Chlorine Level: 1 to3 ppm is a comfortable level for swimming, but if the water is cloudy you want to raise your chlorine level even higher.
Add one gallon of shock per 10,000 gallons of water, in the EVENING or at NIGHT, when the sun is off of the pool. Run the filter all night.
If the water is still not clear the next day, shock again that evening. You may even need to shock a third night, especially if the water started off very dirty. The chlorine gets used up quickly to kill the contaminants that are clouding the water.
2)Low Alkalinity Level: Low alkalinity tends to cause hazy water. Both alkalinity and the pH fall with the acid rain. Alkalinity Balance raises alkalinity; pH Up raises pH.
3) Algae: If you have an algae problem, add a dose of algaecide. This treats the problem more effectively than shock alone.
Once the water is balanced, you can also try a clarifier or flocculant. These products will coagulate small particles in the water and drop them to the bottom so you can vacuum them out of the pool.
Filter Problems
If the water is balanced but still hazy, you may have an issue with your filtering system.
Sand Filters
How old is the sand?
We recommend changing the sand every 3 to 5 years.
Have you backwashed recently?
Backwash once the pressure reaches rises 8 to 10 psi above the normal start-up level (when pressure gauge reads about 20 or 25 psi)
Have you tried a flocculant?
Flock is poured through the skimmer and forms a jelly-like substance in the filter, making the sand more effective
DE Filters
Have you backwashed the filter?
When the pool is especially dirty, you will need to bump the filter and change the DE frequently. Bump the filter once the pressure rises 8 to 10 psi above the normal start-up level (when the pressure gauge reads about 20 or 25 psi)
Have you cleaned the fingers with a solution?
We recommend taking the filter apart, spraying the fingers or grids with a cleaning solution, then rinsing them off with a hose. A solution is much more effective than water alone.
Cartridge Filters
Have you cleaned the cartridge?
Take the cartridge out, spray it with a cleaning solution, then rinse it off with a hose. A solution is much more effective than water alone.
Have you replaced the cartridge?
We recommend changing the cartridge when a solution no longer adequately cleans it.
NOTE: If you notice staining on your liner or concrete, the water has a lime green tint, or you cannot clear your water any other way, you may have minerals in your water, especially if you have well water. Bring a water sample to the store and ask to be tested for minerals.
