Hey, I think I solved my laser tube bubble problem.
Simpler than you think!
I also completed a K40 cooling circuit upgrade as part of the project to move and make my K40 mobile in my shop …
Details here:
Maybe i missing something very obvious but what is the solution. Did you make that impeller youself? Impressive, if i would build it, it would leak for sure 
@Paul_de_Groot check out the link to the blog in the post above. The simple version is I put a drain in the bucket :)!
Nah the impeller is purchased …
Nice post and thanks again for sharing your work. I see you got the air flow meter as well 
@Nedman yes I really like that meter, thanks for pointing me to it! BTW I tried to use it as a water flow indicator but it is to restrictive …
@donkjr What kind of plastic fittings are on the water indicator, mine came with huge metal ones, that were too big for the tubing.
@PrintinAddiction mine came with none. These are 1/4 NTP nylon I think, from home depot.