thx, in air which means in the water there is way less Par, because light have hard time to get though it right ?Even with your current reflector you should have more than enough light.
2 x 39w Odyssea par values (36" fixture)
10.5" (26 cm)130 91 92 85
16" (41cm) - 86 53 63 59.
Not apples to apples comparison but it paints a picture.PAR values for Odyssea 36" 2x39W T5HO
www.plantedtank.net
Measured in free air.
I assume light face to surface.