Chris, watch some you tube videos and observe the water flow going thru the sluice. There is a logical limit to the size of material which you should be dropping into the sluice. Did you run the material through a classifier screens first to sort out the large material from the smaller stuff? The "gold" that you see floating away is mica or pieces of biotite. At first glance it is kind of tricky to your eyes but if you get a piece between your fingers you will note that it crumbles and flakes apart easily. Definitely not gold.