make the one that hangs in the tank a little bit shorter , the A and B piece. Make sure you put a cap on the C piece with a hole in the middle. To start the syphon you suck the air out through the C tube and once it starts you shouldn't have to do it again. I have one of these at home I made recently and works fine, looks identical except those things i mentioned.
And the noise...ahhhh
deal with it. LOL just kidding but idk, i got so much noise in my room but i dont mind personally. I sleep with a pillow over my head. I've heard people say if you but a L piece at the tip of your B, it makes less noise (which I have). But I don't mind much about noise so cant help there. I've noticed the most noise comes from the water gushing into the refugium at bursts. Lemme know if you need more help