wing tank fuel guage

Hello all,

I'm building a mid wing airplane and looking for a clean fuel sight
gauge. I've tried a clear vertical fuel vent line inside the cockpit
for each tank without the desired results. I'm covering the top of the
tanks with Poly Fiber instead of Plexiglas so I can't do the light
access panel over the tank and cut out slot in fuselage to view the
side of the fuel tank. There must be proven ways to monitor tank fuel
levels. I'd love to hear. It's almost run up time.