After the rain tonite, all should be well with your chlorine levels.
Basic pool chemistry...
Always check and adjust Total Alkalinity first: 90-120ppm
Next, adjust pH: 7.4-7-8
Then adjust your chlorine: 1.0-2.5ppm
If that fails and algae continues to grow, get a jackhammer and a bulldozer and fill that f'r full of dirt, cause you shouldn't own a pool
