In flowering how far should led be from plant

I spread my hand out so my fingers are splayed and put my thumb on top of the plant and put the light down to my pinkie probably about 8-10 inch

That REALLY depends on the LEDs. In flowering, you want 900 ppfd assuming you are not using CO2. Look up your light on Amazon, ebay, or another online store. They should contain a "ppfd map", which looks like a grid with numbers in the squares. The numbers are the ppfd. Use the maps provided to figure out the proper height. Again, you are looking for 900 ppfd.

Depending on the stage of flowering and the led light .During the flowering stage LED Grow lights should be located between 16-36 inches from the plant canopy. Moving the grow light closer will increase the light intensity which can maximize photosynthesis.

Welcome to the led world, I would suggest 15 to 18 inches from the top of the plant canopy also look for signs of light bleaching on the upper leaves. If you experience bleaching back the light up slightly. I hope this answered your question. Cheers