Oh thats such a coincidence Tao! Im also about the embark on another venturi for my third pond :D using the exact same materials:

*2inch pressure PVC pipe T-piece with threaded T-piece area (the place where the venturi pipe goes in.
*1inch threaded cap (to be modified to fit 1inch pressure PVC pipe).

I want to ask some questions:

*Was the venturi pipe cut at 45degrees where the 1inch pipe is inside the larger pipe that carries the water? I used iron ring (spacer) for venturi pipe. But it is will be better if you use stainless steel. Then there will be no rust.
*What flow rate are you running through the venturi? In the picture, I used submersible pump at 320 ltr/min. which is actually fit to 1.5 inch pipe (too small for 1 inch pipe). But for PP Bombing, I need water flow and also dissolved oxygen.



Thanks in advance,
Benny