Hi Po,
turn it back on in the morning, and set the output to 30%.
You will need to check FC every day for several days, and adjust the output as needed to maintain your recommended FC. I recommend to keep a record of your FC daily test, so you can see a trend of what your FC is doing. The trend will tell you if you need to adjust your SWG output up or down.
Here is the link to the chart. You need to know what your CYA is (or are now targeting), to know how much FC you need.
http://www.troublefreepool.com/content/128-chlorine-cya-chart-slam-shock