Hi...
I fill up the whole piping with water, then cover up all the outlets.
Then I remove the in and out (keeping the T-joint outlet closed).
This, will create a siphon effect, and water will come up at 'full speed' then I remove the T-joint outlet cap, and the whole piping become 'self-regulated', which mean the siphon will stop when the water level go below the inlet, and start again when the water level increase to above the inlet.
(err...hope you understanding what I'm talking...
Hi crab, my problem is that the water is not able to flush out, it is like slowly flow out. Could it be there are air bubble trap at the varies U junction that is affecting the effect, or the height of the joints play a part?