Strange question

[dacia]

I know the lighting requirements for the corals that I want to have, and the ones that I know I can't have (I have PCs rather than MH). Knowing this, I started to think about life out in the ocean...
Why is it that in the ocean, corals need the sun and can live deeper under the water than my tank is deep...but in an aquarium they need heavy duty light and shallow tanks?
Back in '97 I started college for marine bio...I suppose I would know the answer if I had not switched over to forensic medicine...

 

[bdhough]

Well try looking at the sun sometime with your eyes. Its all but impossible for 2 or 3 seconds without burning them. The intensity of light the sun puts out can't be matched in a home aquarium. Apply that to hallides and pc's You can easily look at pc's and vho's and with a little adjustment mh's. It also has to do with the sunlight direction. Reefs only form in the middle of the earth's oceans where the sun is never very far from a direct arc across the sky.

 

[jauringer]

Thats a really good question. i would be interested to compare PAR ratings from a metal halide to the sun, so I could get a better grasp on just how close we come to duplicating sunlight in our aquriums.