I've got it throttled back to just over half of the pumps capacity, it's not running efficiently yet due to the outlet of the pump is a weird size so the connection I made up is leaking & loosing some pressure and needs reconnecting for a better seal, the size of the holes on the spray bar would also influence the pump greatly but any smaller than what I drilled and it would just create more pressure and overspray, I made up another undrilled spray bar initially thinking I would have to experiment a fair bit but I think I got lucky from the start, I set the angle as a starting point then adjusted the spray to just cover the matting with even flow, I might experiment and reduce the angle by 1 piece of wood and increase the water flow, re-run the material and see if anything else gets caught.
After running 10 litres of cons in the current setup I'm left with about 1-2 table spoons of caught cons for clean up which doesn't feel like it's enough but it's catching fine flour gold so I'm happy with that.
Like G0lddigg@ said, you could build a smaller cleanup sluice and run a smaller pump on it, I could get away with a much smaller pump on my sluice if everything was running 100% efficient but I bought the bigger pump so I had the option of using it for other applications as well, I want to set up my AM Grubstake eventually so if I bring back any buckets of classified material I can run them through the GS with a different spray bar first, crush the material the next day and run it through the cleanup sluice before topping up the garden beds.
I think it's just a matter of experimenting with angles and flow rates, I'm no expert on it by any means but keeping the matting covered via sluice angle V's water flow and re-run the material at different settings to find what you're happy with.
