A long lance 38mm ID mounted vertically into a pool the last 300mm of the lance is bent 45 deg, so the end of the lance is 305mm above the pool floor.

It is supplied by a submersible pump that is 1m below the pool surface and provides 3.5m/s and 4.25 l/s

I'm trying to figure out how far the water jet will travel in the water, before losing all its momentum i.e. How far would the water disperse the larger mass of the pool.

The lances function is to disturb and plume a silt like layer of material that is approx 80% dead plant algii Pond 95 by 35 m by 5m deep.

What would the result of doubling the flow to say 9 l/s?

Would fitting a nozzle or several small nozzles to the lance head improve the dispersal rate?

Any other optioneering thoughts would be most welcome? Would an educator be a better method for example?

Also if you could explain your workings as much as possible i'd appreciate that!