Real Reef 24hrs. (Lighting)

[Mr. Turtle]

I'd like to start a discussion about a real lighting time cycle. It may have been done before but I'm very curious as to why a reef tank cant be lit like real life. I know the results of something like this as far as algae etc. but I'm wondering why this happens in a reef tank with perfect water specs. Is it due to not having the perfect balance or type of fish/critters to keep the algae growth in check? Is it the constant change of water flowing by a specific area in the ocean? it seems to me , especially in a larger tank, that you should be able to build a light fixture that mimics real sunlight from any given dusk to dawn (spectrum, intensity, etc.) and if the water is right then the algae shouldn't grow unchecked. Does our inability to perfectly balance feeding of our fish/critters cause the excess light to turn those excess nutrients into excess algae growth or is it simply the algae's ability to turn light into food? And if so then why doesn't the algae grow like crazy in any given part of the ocean? As bizarre as it may sound...maybe we just don't keep enough corals/fish/critters in a specific tank to eliminate the nutrition/chemicals that algae feeds on?

I know this may take a lot of thought and hurt some brains as it has mine, but if anyone has the time i'd like to have some opinions.

Thanks

 

[ReefingBuddha]

Someone please correct me if I'm wrong but there are a number of fixtures out there that are built to match natural lighting exactly and on top of that some people use solartubes which is exactly what you would find in nature.

Algae is not the main reason why I don't run my lights for more hours a day, I simply don't see a positive correlation to coral growth if I run my MH and t5's for any longer. I've read that there is a level that corals reach during the day where more light is detrimental to them. If you think about it, we have a constant, high intensity light source directly above our tanks for 8 hours. In nature the intensity is at it highest point for only a few hours a day and the rest is build up and down from the point not to mention cloud cover, redirection of light through large waves, and the depths of many reefs.

And to answer part of the algae question, I have no problems with algae in my tank regardless of light source (natural or unnatural) or duration. I've been lucky enough to have no algae problems since I setup my tank and as a SPS tank my water specs are spot on.

I hope that answer some of your questions with reasonable accuracy. Someone please correct me if I'm wrong.

 

[jason9jay]

Many people do try to imitate real lighting cycles, and I believe there are some new LED systems which can actually mimic cloud cover, sun rise/sun set.

I know this is a very basic overview but algae growth is kind of like this...

Algae uses light to create food, and it assimilates nitrogen to make proteins.

When you think about the ocean, it has a very DSB (which can convert nitrates into N2 and release it as gas), and a HUGE water volume. So excess nutrients would be pretty diffused. This limits the possibility of a widescale algae bloom.

In our small reef settings, we tend to get more algae growth with longer light cycles (in some cases) if the nutrients are there for growth. Optimum conditions lead to more algae growth... hence the concept of the macroalgae in the fuge. I use 24 hour lighting which provides the plants with means to grow and to assimilate more nitrates for growth.

Kind of got on a tangent there...
Anyway my question to you is what do you consider to be a "real life" light cycle? I know a recent TOTM had fiber optic lighting, which would mean very close to a natural light cycle. That tank was doing very well w/ algae growth and coral growth(algae low, coral high).

So i guess my opinion is that real life lighting can be done

 

[greenbean36191]

I've read that there is a level that corals reach during the day where more light is detrimental to them.

No. For some reason this is widely believed in the hobby. The rate of photosynthesis is a product of intensity, not duration. It doesn't drop off as the day goes on. It will continue at the same rate as long as you keep the intensity the same, unless you provide light that's so bright that you're damaging the photosynthetic machinery. In that case it drops off very quickly, not after a few hours.

As for the original questions, what's the goal of more closely mimicking natural lighting? Most reef tanks now are much more favorable for fast coral growth and bright colors than a more natural lighting regime would be. Unless you're actually using real sunlight I don't see there being much real benefit.

Also, who said that our tanks have more algae growth than natural reefs. Natural reefs have high rates of algal growth. They also have a very diverse corps of herbivores that keep the algae mowed down to nothing. If you eliminate those herbivores you end up with a situation much like what we have in our tanks- you get algae that overtakes the corals. It's not that it grows any faster in our tanks, it's just that we have to take care of it. Adding nutrients will do the same thing in nature just as it does in the hobby.

 

[jason9jay]

Also, who said that our tanks have more algae growth than natural reefs. Natural reefs have high rates of algal growth. They also have a very diverse corps of herbivores that keep the algae mowed down to nothing. If you eliminate those herbivores you end up with a situation much like what we have in our tanks- you get algae that overtakes the corals. It's not that it grows any faster in our tanks, it's just that we have to take care of it. Adding nutrients will do the same thing in nature just as it does in the hobby.

----> well stated

 

[Mr. Turtle]

It's funny...I wasnt actually looking for an answer as i had my own theories. the replies i got were exactly the discussion i was looking for. I knew the LED's could mimic real sunlight although i hadnt really understood that they mimic'd natural sun light including cloud cover, dusk, dawn, etc.

Is our goal to keep coral for our viewing pleasure or to grow it as nature intended so that we may say we have our own private chunk of the ocean? Im sure some people keep for the incredible view and some for the actual natural ocean.

My view is the one that the dilution and perfect natural balance is what keeps "too" much sunlight from messing things up. It would be incredible to keep a chunk of ocean exactly the way God/nature intended. could we afford to buy the replacements for when they run out of food or get over eaten by critters placed in the tank to keep them from "over" growing.

Do we try to keep the perfect sustainable balance with keeping the exact items needed to make it work as nature? which parts can we leave out and still have the balance? does our man made filtration take the place of certain critters needed to keep algae, etc from over growth.

It is amazing to me that we can keep "chunks of real ocean" and substitute our way to balance it without the natural items/critters found in the real ocean. Next time you go through these forums just look at all the ways we adjust our private chunks of ocean to make up for all the pieces we cant afford/find/keep.

Will there come a time when our tanks look exactly like what we see when we dive in a clear blue ocean and see "our" corals, fish, and critters in their natural environment?

 

[greenbean36191]

It's clear that there's very little attempt to mimic real reefs. If there was, people would have 120 gallon tanks with 3 large, brown corals of the same species and a fish. I doubt that look will ever be popular. Our tanks have small, unusually brightly colored, densely packed corals of more species than you would normally find on an entire reef, much less a few square feet. Invertebrate diversity is incredibly low. Fish diversity is pretty low too and mostly limited to small, non-aggressive species. They also tend to be densely packed. All of this is usually combined into combinations that never occur in nature.

We don't even come close to replicating the look, much less the function of real reefs. The first is possible, but not something most hobbyists would enjoy. Replicating the function of the reef would require us to understand how it works in nature, which we aren't even close to doing. We will probably never get to that point before reefs are gone. Beyond the lack of understanding, some things (like the territorial needs of some fish) just can't be scaled down.

 

[jason9jay]

Yeah, I know what you mean. We pack fish together that are from different oceans, and from completely different depths. I can see what Mr. Turtle means about the "true reef lighting" now, as our tanks have lights that we pick to "enhance" the quality of viewing our coral.

We've come a long way from how original reefkeeping began.... i mean most of us have biological filtration as opposed to chemical(because an aquaclear hang out just won't cut it in SW), we dose live phytoplankton, and we measure trace elements which weren't even considered to be important years ago...

I am kind of wondering what the next major breakthrough will be.... and what kinds of things we use now will be phased out? I feel like lighting is going to be the next major change before any new big ideas come out in filtration. T5s and LEDs are paving the way into a new lighting future...and possibly more with fiber optics?