Two questions protein skimmer and power head shaft

[Fishlover56]

Hiya
my skimmer is a hang on one just wondering where i should position the bubble level as its still breaking in the microbubbles realised back Into the tank is slowly going away

also my power head ceramic shaft broke i have some stainless steel rod the diameter laying around could i use that to build a new shaft if i cut it to the right length

thanks for the help!

 

[Saltyreef]

Would not use stainless steel for impeller