Aluminium pipe for growing?

I was thinking of making the samekind of system that Heath uses. Im a little bit out of money, but i have lots of duct hose/aluminium hose left, it´s perfect diameter also. So can i use this hose or is it bad/dangerous to the plants?

https://www.rollitup.org/hydroponics-aeroponics/149998-heaths-flooded-tube-vertical.html

Thanks for your help.