Initially I got inspired after watching this video: https://www.youtube.com/watch?v=L6ArUM_hTtA. I made this improved version with two more T’s without drilling any hole. Then I saw another Youtuber to build a similar device – sorry I cannot find his video URL.

I also find that you do not need to take out the transparent vinyl tube to get it primed. Simply submerse the whole thing in water and make sure there is no air in the vinyl tubing. That’s it!