Sunlight on the reef aquarium

At the meeting last night, a discussion started regarding whether UV(ultraviolet) sunlight comes in through the window to help clean the water and control disease.
I believe that it does. The result is that rather than lose many fish to an epidemic as some have experienced, I lose only an individual fish here and there.
Whether this is the result of UV light or other yet unknown characteristics of sunlight on a reef, I don't know.
What I do know is that sunlight on my tanks looks awesome, especially in the bright morning sun. These tanks seem to be healthier and more vibrant because of the sunlight.

Ryan Thompson wrote: There is a guy over on RC that built an outside room and used greenhouse material for all the windows. His tank is totally lit by the sun and it is an AMAZING tank.

Ohhh I remember that thread! His whole greenhouse operation is awesome. If you haven't seen it I highly suggest you read through the thread. It shows exactly what you CAN do with sunlight alone. Seriously awesome.

Corals don't put up a "protection layer" against UV. The colors you are seeing is usually protein and some algae.

The glass shields on MH bulbs blocks all of the UV.

Ryan Thompson wrote: Corals don't put up a "protection layer" against UV. The colors you are seeing is usually protein and some algae. There was an article once that stated that the color of a coral was its' "sunscreen". That was later disrpoved. T5's put out very little UV and like you stated, MH's have a glass shield to filter out UV. You don't want an unprotected MH bulb blasting your tank. You will kill your corals doing that.

Can I get a link to the "disapproval" of this following science?

"Corals that live in shallow-water are typically exposed to high levels of potentially damaging solar radiation. In addition to this potential damage from the sun, the coral's situation is made even more difficult by the release of oxygen that is produced by the algal symbionts (zooxanthellae) during photosynthesis.

Even with these potentially damaging scenarios, coral animals are able to withstand long-term exposure to damaging amounts of ultraviolet radiation from the sun. Scientists believe corals posses a compound that acts as a type of sunscreen for these organisms. These compounds, known as mycosporine-like amino acids (MMAs), have the ability to efficiently absorb UV light. Corals are either able to accumulate enough MMAs, either through producing them or accumulating them through feeding, to protect themselves against the strong solar radiation that is typical of tropical areas. Researchers are even investigating the possibility that these MMAs may be able to be produced to provide another type of sunscreen for humans.

It is the UV light that gives most SPS corals their brightly colored tips. These colors are actually a natural type of defense against harmful UV light. To date only reasonably strong metal halide lighting can produce enough UV light to "fool" SPS corals into producing this defense. SPS corals will grow and even flourish under different types and lower intensity lighting, but the fluorescent tip colors will be lacking or much paler in color."

I think this came to life last year, so was interested to see when this was considered false....

Ryan Thompson wrote: The glass shields on MH bulbs blocks all of the UV. Tanning bed lights and aquarium lights are two totally different things.

What we're really talking about here is sunlight.  Yes tanning bed light may be different from aquarium lights.

saltlaketank wrote: Ryan Thompson wrote: The glass shields on MH bulbs blocks all of the UV. Tanning bed lights and aquarium lights are two totally different things. What we're really talking about here is sunlight.  Yes tanning bed light may be different from aquarium lights. But the question was can UV pass through glass??? Well yes it can as it does in a tanning bed.  Likewise the UV from the sun passes through your window, that's why you can get a sunburn driving to wendover with your window up.