Marine Aquarium Lighting

Question
A friend told me that enough sunlight will let live rock live instead of purchasing an expensive light source, is that true?  Like if I put my aquarium near the glass sliding door at my house?

Answer
Joseph,
While it is true that you want a replication of sunlight in an aquarium, direct exposure to sunlight is going to cause more harm than good.

For one, you can't control the duration of light that the tank is getting.  So, now that it's getting late in the summer the days are getting shorter and so you're tank will be exposed to less light.  This is bad for animals that rely on the light for feeding.

Two, direct sunlight in conjunction to regular aquarium lighting tends to cause enormous algae blooms.  So, if your intent is to create an algae farm then I'd say go nuts.

Finally, depending on what else you are planning on keeping in your aquarium sunlight tends to not be at the correct intensity with the correct spectrums.  Granted if you lived in a tropical place such as Hawaii you might be fine, but even then the sun would produce too much heat and kill most of what you have in your aquarium.

These are just a few of several reasons not to keep your aquarium by any windows or to use natural sunlight as a source of light.  If you need more valiation please feel free to pick up any beginning aquarium book and they'll confirm my suggestion in the tank selection and placement chapter.

Best of luck with you tank!

Regards,
Scott Johnson
Aquarium Crazy Fish
www.aquariumcrazyfish.com