Quote :

Would there be no need to put pipes circulating water at the bottom of the pond as well? Or will the circulation created by the venturi's suffice?

In my experience dirt always collects underneath a venturi or jet when placed underneath water....except if the floor is sloped. A venturi is not the best device to create current under the water...it creates current on the surface but due to the restrictions inside the venturi (50mm to 20mm) it does not have real pushing power underneath the water - a water jet with no restriction (plain open pipe return) will be better.


The americans use inlets at mid level range called TPR's aimed at the sides of bottom drain. These inlets are angled to move dirt towards the bottom drain. They use two of these type of returns per bottom drain. In the examples i have seen they all seem to be in the 32mm pipe range.

The current from the one TPR is directed to pass the bottom drain on the one side while the other TPR on the opposit side pushes water in the opposit direction on the other side of the bottom drain...thereby creating a sort of a vortex around the bottom drain.

Cam0,

If you place the venturis above the water line as suggested, a current will develop in an anti-clock wise direction; the current will force the debris to the middle of the pond.

(Take a bucket with clear water and place a few small stone in it, and then by using a hosepipe adding water to the surface of water in the bucket to form the current, you will notice that the small stones will settle in the middle at the bottom of the bucket after awhile).

Thanks for the advice guys.

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Would directing the venturi's length wise and not width wise in the pond have any effect on current creation?

No/ Yes?

Cam0,

No