As long as you're within the normal ranges for bleach, it shouldn't be a problem on the grass.

BTW, Dichlor is basically bleach + cyanuric acid in one. You won't need both dichlor and bleach; one or the other will do what you need. Just make sure you dose appropriately. If I calc your dosage properly, it's only about 9oz of regular household 6% bleach or 1oz of dichlor to get you to 3ppm FC in the water volume you describe.

You should read these two docs before you get started:

http://www.poolsolutions.com/gd/the-...pool-care.html

http://www.poolsolutions.com/gd/best...ine-chart.html