One afternoon a customer called to tell us that the light level we had recommended for his setup could not be correct.  He had inquired about a 90 gallon freshwater planted tank and we had recommended a 4x55watt setup for him.  Now we know that our 4x55w setup is plenty of light to grow plants well in a 90 gallon, so when he assured us that it wasn't in his case, we quizzed him on his setup to see what could be wrong.  Turns out he was only an A H Supply customer for his bulbs.  He had taken our recommendation but applied it to his selection of a "great deal" he found elsewhere. 

This customer was good enough to point us to the source for his lights online and as soon as we saw the picture we could pretty well guess what the problem was.  The lighting unit in the picture showed the compact bulbs installed very close together behind an opening not much larger than the space the bulbs occupied.  How could the up-light from the bulbs ever get out of the fixture to become useful down-light for an aquarium? We decided to buy a 2x55w version of this fixture to see.

When the fixture arrived, we loaded it and our 2x55w kit with fresh 6700K bulbs and did a quick test of the light 16 inches below the bulbs.  The fixture we purchased turned out to be even less efficient than expected.  What we found was that the A H Supply 2x55w setup produced slightly more than 2 1/2 times as much down-light. 

This means it would take a 10x55w setup of these fixtures to nearly equal the effective light of the A H Supply 4x55w setup.  Efficient lighting depends on doing a number of things well.  This fixture doesn't really do anything well.  It's ridiculous.  We could see why the caller didn't find his 4x55w setup adequate.

Hidden Costs

This got us to thinking about the real cost of the "great deal."  In the case of a 10x55w against our 4x55w the problem is obvious.  But what about the case of smaller tanks where the 2x55w fixture we purchased might be adequate? 

We tested this 2x55w fixture against our 1x55w Bright Kit and found that our 1x55w kit produced 30% more light.  Even if you didn't need that extra 30%, consider the costs of using twice as much electricity as you really need to use and twice as many bulbs.  Over a five year period we calculate that the operating costs of the 2x55w fixture would likely be about $141.28 greater than operating our 1x55w setup.  This assumes 12 hours a day of operation, bulb replacement three times at $18.99 per bulb and $.07 per kilowatt hour for electricity.  The extra expense will be significantly higher in places like the Northeastern U.S. and California where $.07 per kwh is only a distant memory.

And there were a few other things we noticed about the 2x55w fixture we purchased.  No warranty.  No address or phone number for replacement parts. Bulbs holders sized for larger diameter tubes.  Required disassembly to remove the protective film from the reflector ( though we had to disassemble it anyway to try to get the ballast wires to stay connected to the bulb pins -- there's no socket or endcap). "Great deal" indeed.