Maybe mine just came with a weak pump as it doesn't move enough water to clean the riffles unless the pitch is much steeper. Tried a few tests but lost gold with a steeper pitch. I ended up testing it with an additional water hose running into it at about the same flow as the pump and it worked great so basically I doubled the flow to get it to work properly. Processed about 5 gallons of some Montana pay and recovered just under a1/10 of a gram of gold along with some small garnets. I then added an 18" extension because I found gold behind the last riffle and ran another 5 gallons to test it. Found just over 1/10 of a gram so it seems to be catching most of the gold. Overall a fun little unit but needs more water flow so a larger gph pump would help. A 2 gpm (1200 gph) unit seems perfect. Have fun!
My first use was really good, it caught all the gold ran through 100% and it was super fine powder to large chunky flakes. I panned out all the run off from the first run and not a spec missed. The 800 gal/hour pump had more pressure than my garden hose way better than expected, and its durable. Only issue i had was the legs do not stay tight if tightened by hand and i recomend a larger battery i bought the cheapest lawn and garden box battery from auto zone for 30 dollars and ran for almost 3 hours roughly probably more without it even slowing down a bit. Good durability overall handled larger rocks well and not to many snaller ones would catch in the grid
Ran 2 bags of paydirt and collected the tailings. Panned the tailings and found zero missed gold.