LEDs and SPS Ability to Regrow/Repair After Injury.

[AcroporAddict]

My intention for this thread is not an LED Brand debate, but a particular aspect of SPS growth under LEDs vs Halides.

There are lots of LEDs being used by members of my local Reef Club, including myself. My general experience with my LEDs is that the overall growth rate of SPS under my LEDs (Radions) is not as fast, but the colors are similar to a Radium halide bulb. I am a former radium halide user as well.

While some may have opinions on LED brand A vs Brand B, one guy pointed out that what he has observed is that when he used Radium Halides he could nurse a sick or injured coral back to health much more easily than he can under his LEDs. This observation seems to span several different LED brands with members of my local club, and also spans my own. When I have had a coral that has gotten injured, it sometimes doesn't get better and goes up in smoke, whereas with Halides sick SPS corals do seem to respond and recover faster.

So do any of you have this type experience? My own experience tells me that growth is faster under halides than LEDs, which has not bothered me since the SPS colors are there, but can slower growth also mean slower recovery from injury? Makes sense to me.

[djkms]

I tend to agree with this statement. I run LED's exclusively and a buddy of mine has a similar system but much newer (only setup for 6 months, going on 2 years for me) and he runs halides. We would both get corals from tank breakdowns and such and the corals going into his system seem to recover much faster even though I have more mature water.

Interested to hear others results.

[jcw]

A corollary of your theory that i have thought to be true is that corals under leds are less tolerant of changes to the system in general. Temp, light, nutrients, infestations, etc.

[mussel and hate]

If the spectrum an intensity of the output of a particular LED array approximated that of the Radium bulb why would there be any difference at all?

[AcroporAddict]

If the spectrum an intensity of the output of a particular LED array approximated that of the Radium bulb why would there be any difference at all?

The presentation may be near that of a Radium halide bulb, but the difference may be the PAR levels, meaning that what most folks are seeing is lower PAR from LEDs vs halides, even if the presentation is similar looking.

Another member of my local reef club thinks it also may be related to a lack of UV in LEDs. Per him, most, but not all UV is filtered out of halides by the glass bulb on SE bulbs and the pendant glass on DE bulbs, whereas there is no UV at all on the majority of LED fixtures, particularly Radions and AI Sol Blues.

A trend locally for us is many folks have given up on LEDs and returned to halides after using them on their tanks for many months. Complaints of color and too slow growth with SPS being the main issues. SPS not being able to rebound from injury under LEDs as well as under halides is just another, more recent observation.

So as not to appear mysterious my local club is the Atlanta Reef Club, and we have a lot of equipment junkies there, me included. We've had quite a few threads r/t LEDs on our club forums over the last 9 months.

[mussel and hate]

I'm still a MH guy but I'm building a list for an LED buy myself which is what brought me to this thread.

I've noticed more diversity in the spectral output of LEDs available to the hobbiest in recent months. It seems one needn't settle for the presentation of a lamp but can actually mimic the spectral distribution accurately.

If the sellers claims are sincere then emitters are available from Epileds with spectral peaks at 400-410nm, 410-420nm, 420-430nm. Phillips Luxeons RB LEDs can be had with a 440-450nm peak. Cree XT-E RBs are binned between 450nm and 465 in 2.5 nm increments. Blue LEDs between 470nm and 495nm are available from a variety of manufacturers as are the rest of the spectrum all the way on up to Luxeon's 680nm far red chips.

Edit:

Perhaps the arrays showing inferior performance aren't full spectrum but merely White/RB two emitter combos.

[pfi$h]

This is an interesting discussion, however, you have to compare aples to aples. There are too many other potential confounding variables that affect coral growth (water quality, flow etc...). You would have to set up an experiment that utilizes the same parameters (system) with the different lighting and then compare results. Just my thoughts from a more scientific perspective.

[rwb500]

a few bits of anecdotal evidence is not enough to override the complete lack of a proposed mechanism. A hypothesis needs to include a mechanistic explanation.