Ok, here is the write up I did for another member when he asked about bulb change, or switch to LED.
If you are considering performance alone, I think LEDs have a ways to go before they are ready for long term sps.
I guess it depends on what is important to you.
The way I look at it:
I made a conscious desicion to keep these animals as pets. Considering it is next to impossible to replicate conditions found on a reef, I feel it is my duty to try to get as close as possible, yet still making the aquarium a pleasurable experiance.
I considered my choice to try LEDs a selfish choice. I was fascinated with heat reduction and energy efficiency. When it came down to the health of the coral, I would say it seemed mediocre.
These animals cannot choose which light the owner of the aquarium chooses, but they will respond differently to different light sources.
My logic: if I need a full balanced meal every day to sustain life, what quality of living would I have if I was only provided with one of the food groups?
For instance, let's use dairy. Dairy is a readily available resource, it's cheap, and easily renewed.... But how many bulls do you see leaning down to take a sip? Zero. That's because the fats and proteins found in cow's milk are designed for a baby cow.
Many adult humans develope a lactose intolerance. This Is because our bodies were designed to only need the proteins and fats found Milk during infancy. Over time, and with the popularity of milk, humans have evolved to have tolerance to lactose even as an adult. This is something that is passed down genetically.
In cultures from the east that don't drink cow's milk, they would get terribly sick if they drank milk. Drinking milk is not part of their culture, and many of them have never had cow's milk.
If these people from the east suddenly substituted one of their food groups for dairy, how do you think their body would handle the change?
I wonder what response you would recieve if you asked the GA aquarium about whale sharks' ability to adapt to a diet that is not natural to them.
Where an I going with this information?
Though living things have the ability to adapt to new environments, it takes a long time.
In my experience with LEDs, some corals took off in growth, others did nothing. I took some of the corals that looked bad, and put them in conditions that were way less then ideal, but had t5 lighting. Every single coral made a recovery.
With pristine water conditions, and ample amounts of food, why would these corals do poorly? Why did they make a complete turn around when moved to a more polluted environment? Were the lights the key factor? Maybe, I don't know for sure.
What I do know is that the human body needs vitamin d in order to absorb calcium. Without enough vitamin D, one can’t form enough of the hormone calcitriol (known as the “active vitamin D”
. This in turn leads to insufficient calcium absorption from the diet. In this situation, the body must take calcium from its stores in the skeleton, which weakens existing bone and prevents the formation of strong, new bone.
Our bodies get vitamin D from three ways: our skin, diet, and supplements.
Corals derive most of their vitamin d from the uv spectrum of the sun and diet. Taking away a crucial source of vitamin d probably slows the ability for the animal to absorb calcium. This Is why I believe that the LEDs that are marketed today are not able to produce the results(for SPS) that the other methods of lighting yield.
