Flow Indicator

I am looking for a flow indicator similar to the $17 Innovatek one for 1/2 ID tubing. I know this question has been asked several times but it has never really been answered(that I can find). The previous answers given refer the poster to the $40 Innovatek flow meter or a $400 digital job from some industrial supply company. The 5mm is too restictive, and $400? Come on. Somebody out there has to make a simple little visual wheel, just like Innovatek, but for larger tubing.

some 1 made 1, i believe it's on O/C's front page under water cooling.

tiny strips of mylar works
ie. Christmas tinsel