A little background: Previously the water pump injects water towards the middle (looking from above). Water hit the tumbler wall and forced upwards creating convection circulating currents. After cleaning a couple of bird nests, I noticed a dead spot (at opposite end to the overflow outlet) was trapped by eddy currents at the surface. Fine feathers trapped here were not flushed out.
What's the solution?
This is resolved by off-center the pump in order to inject water circumferential to the tumbler wall shown below: (I sourced for a more compact container that fits the tumbler & pump nicely now)
The result now is water circulate upwards with a spiral motion. It also spins the bird nests within - like a washing machine! So I am quite happy with this set-up now.
Some skill required to cut an oval hole of the right size. Handy people out there can surely do it quite easily.
Perhaps I shall rename it as "A Bird Nest Washing Machine"! ;o)
