A normal sluice is 10" buy 40" and water flow is what you have at were you mine .From what I know the question you have asked is for dredges and highbankers were you have control of water.

Thank you for pointing this out to me and my apologies for using the wrong term. It will be a high banker controlled by a pump.

Flow rate is going to be a factor of width, drop or angle of box, type and height of riffles, catch material under them or if you go with a Gold Hog type mat, what type of mat and such.  Even the material you are running can factor in.  Probably want to look a a 2 inch pump or something in that range, you can always run it at a lower speed and cut down the flow rate.  As far as figures, don't have any, it will be play by ear and eye as you run. Start your run with a catch tub and quick pan the tailings to see if you are blowing the good stuff out the bottom end.  Look at the specs on the commercial units and the pumps they run for a starting point.

 

I was playing with the idea of a mini non recirc banker about 7 inches in width, and was told the HF 1 inch pump at 37 gal/min was a little too light on flow.  This was from one of the guys at Royal.  Since I can't pack a bigger pump anymore I scrapped the idea.

 

Just my thoughts on it.

I have seen a double sluice that I really liked, and it was handmade. They used Gold Hog mats for the first 40" and then a traditional miners moss and riffels for the second 40". Granted it was a long box but it was set up to not only capture the course gold, but also to catch the fine flake.

From what I have seen of the Gold Hog mats some of them really allow you to put through a great deal of material and quickly, but knowing the area in which we dig I know a lot of flour and flake is being washed out, and that is why the combo was the best of both worlds for where I live, but maybe not for where you live.

When it comes to flour, flake, and water pressure I have to completely agree with Arthur, you are going to have to test your setup and see how far down you are finding your materials, and the best way to do this is to take a sample, bring it home, and set up kiddy pools to setup your equipment and test your setup. This way you can catch your finds that are washed away and run them again at a different pressure. This way you will be able to determine exactly what you lost and change your existing setup.

Let me add to this just a bit. Two weekends ago my wife dug a lot of materials and found a nugget, but when we panned out the rest of the materials the results were the worst I have seen yet on this river. We can't find a reason to proceed further on this claim. If I go about 30 miles upstream it has the richest black sands I have ever seen, plus nice gold that is a bit chunky. But if we go another 10 miles upstream I find flour and super thin flake that floats.

The gold changes wherever you go, just make sure you can make adjustments to your setup and always test your technique in a new area. The best way I know to do that is at home in controlled conditions.

I know of more than one prospector that brings their materials home and only run them at home, just get a few extra buckets and never fill them over half way. This is how we sample ourselves.

i RUN A 11/4 INCH PUMP FROM HoNDA ON MY HIGHBANKER .It is 10"wide and 40" long and only run it at half throttle .And I run 50' of hose.It has a keen pump on it.

Thanks everyone for all the info. It was very helpful