Who needs incentive to keep a pool sparkling and blue during the heat?
Well, in Tucson they are asking residents to report green pools and water that has been standing for 3 or 4 days due to the prevalence of West Nile Virus!
Of course we recommend keeping your pool blue for entirely different reasons:
1) Gosh, who wouldn’t want to be taking a dip during the summer if they have a pool?
2) It’s cheaper to keep a pool blue and chemically balanced than to have to shock treat it (and possibly overdo it).
Here’s to a splashingly cool summer 
Source: http://tucsoncitizen.com/hot-off-the-press-release/2010/07/20/residents-businesses-needed-in-%E2%80%9Cfight-the-bite%E2%80%9D-prevention-efforts/