I am doing the BBB method. After adding bleach---how long should I run filter ?
I cant run it 24 hours due to dedicated electric not set up yet. Pool guy told me I need to run it 24 hours or it could bleach skin. I could run it 4-5 hours on 1/2 hp

Run the pump for at least an hour after adding chemicals to make sure the chemicals are throughly mixed in.

There are other occasions when it is important to run the pump for longer, but none of them appear in anything you mentioned. For example you run the pump for 24 hours after adding salt. You also need some minimum pump run time based on the relative size of your pump and your pool to get enough filtration, but that is rarely anywhere near as long as 24 hours a day.

If you tell us more about your situation, we can tell you more.

Do the world a favor and point your "pool guy" to this website!

My situation is just putting bleach in the pool. My pool installer worried me a bit when he said I have to run the filter for 24 hours after putting bleach in

No need to run for 24 hours. Add the bleach slowly into the return stream to allow for good distribution and then allow the pump to go for about 1 hour more and you're good.

You should maintain about 40 to 50 ppm of cyanuric acid in the water to help keep the FC loss rate down.