Planted Tank VIP
Join Date: Jul 2002
Location: Winston-Salem, NC
Marcel is right, and in addition, there are a lot of different reflectors out there. Some parabolic units reflect up to 98% of the light down. A flat piece of polished aluminum will only reflect 55%-65% into your tank (only slightly better than no reflector at all). An reflector shape isn't the only variable affecting useable light - the distance from the bulb to the reflector must also be optimal.
Short answer is: It's nearly impossible to put a number on it. But without a reflector, you'd only using around 30 watts of the 60 watts you were using.
- Sam P -
plantedtanker in limbo - all tanks currently in storage