A large contributor to your water chemistry issues could be algae in the water. There are many different types of algae: mustard, green, and black (and every color in between). Some algae can give water a greenish tint and black algae usually grows to produce individual spots. Typically a good chlorine shock will remove algae. If the problem persists, it might be necessary to scrub the pool with some acid. Alagecides can also be used to fight and prevent algae growth. For more information about treating algae check out our resources here.
Mustard Algae
This appears brownish or yellowish. It brushes off the pool walls easily but it also returns easily. It likes to grow in shady areas with poor water circulation. And unfortunately, it resists chlorine shock treatment!
How can I get rid of mustard algae? use an algacide WITH your chlorine shock. Make sure to follow all the label directions.
Green Algae
This is definitely the most common type of pool algae. Like the mustard algae, it likes to grow in areas of the pool where there is poor pool circulation. Although it really can appear anywhere it likes. It also grows rapidly.
How do you clean up green algae? Again, use an algaecide along with a chlorine shock and follow all the label instructions.
Black Algae
The black algea is the least favorited of all pool algae. It is very resistant and stubborn. It can cling to the pool walls, floor, and all cracks and crevasses. It really likes to thrive in gunite and concrete pools. The longer the algae is present, the more difficult it will be to remove. It is best to treat this type of algae as soon as possible. Black algae can pit the finish in a gunite pool.
How to to treat black algae? Brush the algae spots very vigorously with a stiff algae brush and pour algaecide along the sides of the pool. Run the filter continuously and then finish off with a chlorine shock. It is best to treat with a high-powered algaecide such as Black Algaetrine and follow all label instructions.