Testing kit for pH and Chlorine level:

Recommended levels: pH 7.4-7.6, Cl2 1.5-2.0
High pH and Cl2 level causes your eyes to burn because the water is acidic. Lower pH and Cl2 level causes Algae to form and bacteria as well. Clarity of water is not to be used as baseline of cleanliness, as there are chemicals like Alum that pool maintenance people used to add that "sparkling" clean look at the pool. Send water sample to lab for testing of bacteria.

It's not because things are difficult that we don't dare, it's because we don't dare that makes things difficult!