Not a bad video! You are getting Gold but I wonder how much you are losing??!! I noticed that more than half of the upper riffles in your' sluice were clogged with rocks and debris. With that much rocks and debris clogging the riffles, I am certain a lot of the Gold is washing over them and out of the sluice before they have time to sink and settle. Try raising the angle on your' sluice next time to prevent the riffles from clogging and I am sure that you will see better results. The water flow appeared strong enough but if the riffles still clog after raising the angle of the sluice, then you might want to increase the water flow.
Good luck!
Frank