Anyone use natural sunlight for lighting?

[jgln]

I saw a huge tank in a magazine where the guy used natural sunlight as a main source of lighting with good results, but that was a huge tank. Anyone use it for smaller tanks (125-180) with success? One concern I would have would be heat from the sun.

[mwhite]

Many of the tanks at the Waikiki Aquarium use sunlight for their illumination. They also have a coral tank and a clam tank outside in full sunlight.

My tank gets late afternoon sunlight for a few hours each day with no problems. The sun definitely outshines my double 250W MH lights. The only problem is that my bubble tip anemone prefers that side which makes him hard to see.

[rockindacheeks]

some people have tanks set up using solar tubes (reflective skylights) for primary lighting and supplement that with some actinics.

[stupac21]

I have been keepin the shades open on the window next to my tank lately.

My corals have seemed to appriciate it.

[Grunt]

Many coral farmers/GH owners use sunlight. I have seen them used in smaller applications by use of the tubes. Even on an overcast day they provide enough light.

my 15 gets indirect sunlight from across a room. The corals love it.

[jgln]

Thanks for the input! I'm going to try and incorporate natural sunlight into my new 125L tank when we set it up in the new house with an option to close off the sunlight should it present a problem. I'll have to look into the solar tubes mentioned, never heard of them.

[RBU1]

I thought the beneficial part of the sunlight was filtered out by the glass.

[jgln]

Do you mean the light through the solar tubes (solatubes) or the tank glass?

[RBU1]

The tank glass.....I am almost positive someone told me that.

[chrisqueenz]

Really? Would be beneficial to know if it does or not.

[mwhite]

Regular glass is opaque to Infrared light (heat), which is why it is used in greenhouses, and to most Ultraviolet (UV) light, which is why you need a glass cover over an unshielded MH bulb.

[conchead]

my 120 gets 3 hours of direct sunlight in the morning,seems to like it.

[jgln]

No heat issues huh?

[MrSpiffy]

Originally posted by mwhite
Regular glass is opaque to Infrared light (heat), which is why it is used in greenhouses, and to most Ultraviolet (UV) light, which is why you need a glass cover over an unshielded MH bulb.

Actually, the glass cover over unshielded MH bulbs needs clarification.

Those shields are made of tempered glass. That makes a HUGE difference. You can get a sunburn through normal glass, but not through tempered glass. I'm sure it reflects some of the UV rays, but not all unless it's tempered.

Also, only the HQI's (double-ended bulbs) need tempered shields. The mogul bulbs (single-ended) have UV protection built into the bulb's glass. You might consider a shield anyway in case of splashing, so it doesn't explode and spray glass into your tank. But you shouldn't NEED a shield to run single-ended bulbs safely.

In any case, if I had the option to put my tank in sunlight, I definitely would. I've seen tanks in direct sunlight, and it's nuts how the light-loving corals love it. How could anything beat the sun? After all, God's tank uses the sun!

EDIT: I stand corrected. Tempering of glass does NOT seem to affect it's UV blocking capabilities. Glass does tend to block roughly 70% or so of UV light (depending on the thickness of the glass), but it does not block all UV. In any case, the reason you need a glass shield on DE bulbs is because they're made of quartz, not glass, and therefore do not block UV rays from penetrating the bulb. SE bulbs have glass, not quartz, and therefore can block most UV rays. Tempering is only so it can safely withstand higher temperatures. So I was partially correct, and partially incorrect. Sorry for the confusion.

Here's a discussion thread in another forum I found to clarify things a bit: Reefs.org topic on UV shielded glass

[jgln]

I stared this thread because I may have the oppertunity to place our tank in direct sunlight in our new home and wanted experienced feedback before trying it and so far it'a all been positive (I also didn't want to have to move a 125g if it was a bad idea).
I also started it because it has always amazed me how much we all spend trying to duplicate what is just outside our homes. For the money we could have build a sunroom for our tanks. But then we'd probably spend money on the AC from the heat produced there.
One other thought is this far north where I am the light in winter may not be strong enough as the sole source of light, but as a supplement it sounds like a good idea.
Thanks for all the advice.

[boxfishpooalot]

Above is a spectrographic image of the sun on a cloudy day taken from my area. Imo I would include the sun in any tank simply for the fact that you get ALL the colors in the spectrum, and lots of Par.


Here is t-5 whites.


Above is a 20k 400 watt metal halide. Notice its missing parts of the spectrum that only the sun provides.

[boxfishpooalot]

Here is t-5 blues, or actinics. Not very good imo for growth and health of photosythetic animals.

[Tate]

My corals love the direct sunlight they get for two hours in the morning.

Unfortunately, so does the brown aglea.

[Grunt]

One thing you should be cautious about when placing a tank near windows is algae growth. Can get quite ....hairy :-D

cheers

Oh btw the Florida aquarium grows corals in direct sunlight on thier rooftop. Its like a GH operation.

[davidryder]

If the tank has line of sight with the sun and you don't experience shortened daylight periods during winter and fall I don't see why it would be a problem. But direct light, as in overhead, and tropical photoperiods that are fairly stead throughout the year. I would be disqualified here in Cincinnati

[vijaym85]

boxfishpooalot Cool images.


I use natural sunlight to wake up my corals. My room is on the east so as the sun rises I let the light in. The tank is next to a window on the 2nd floor of my house. The corals seem to respond as much as they can with the amount of light entering. I will try to plan my next tank to use sunlight in a bigger way if possible.

[Tony44]

If I were to get a small tank, and place it outside so that it gets natural sunlight, what could I cover the tank with that wouldnt block the sunlight, but would stop the rain?

[Frick-n-Frags]

the tropicorum in michigan is a greenhouse prop setup basically


also, surface sunlight spectrum is not the natural spectrum of corals 10 feet under the water. the red and most of the yellow has been attenuated, so that last t-5 pic is closest to the coral's natural light spectrum with the majority of blue and purple (actinic and near-UV penetrate the deepest into the ocean) with a nice shot of mercury green in there, which is also strongly represented in shallow reef light.

sunlight is lots of PAR, but it can cause algae problems sometimes
like any other 3000K bulb would.

[pluvialis]

one side of my tank gets direct sunlight. That is the only place hair algae grows. Recently , I have een closing the shades to see if the HA goes away. Corals love it the intense light. Happy to see this thread!