DOH! I got all excited when this thread appeared in my Facebook feed. Based on the topic, I had hoped it would be thread on spectral balance, intensity, PUR/PAR, on/off cycle and timing, effects of lights balance on various color morphs, etc. I guess, when I reread the topic, the thread probably does meet the intended goal of the OP.
I have to get to work but I'll take a moment to flap my lips on the topic of what is, IMO, the fundamental flaw in most of these conversations.
Regardless of what personal logic one utilizes, the bottom line, is we are discussing photon engines. The frequency, volume and overall spectral balance of the photon stream changes, but a photon is a photon regardless of the source. Nothing anyone posts, regardless of how many paragraphs it takes or the elegance of the prose it is coached in, changes that.
If you want to figure out lighting than IMO you need always remember that. Do not allow yourself to get sidetracked by threads filled with opinions and personal stories. While your degree of success or failure maybe altered by opinion and personal stories science is not.
Hence the choice of light engine is likely the least significant issue as long as the engine(s) utilized can produce light with the correct balance of spectrum at the right intensity at the required water depth and it is timed appropriately. From that point forward the discussion would deal more with fine tuning the implementation of those light engine(s) to maximize results.
It was no surprise to most experienced reefers that early adopters of LED's were disappointed. Most early LED's were inadequate in most areas and that should not be a surprise as the chips used were simply re-purposed from other fields. Almost all of those first LED's were some approximation of the actinic spectrum combined with 10,000 kelvin chips. I know from first hand experience that many of those strips, even some of the biggest and most successful, were re-purposed architectural landscaping up-lights that were repackaged. Those first LED's, and by first I mean the first 5 years, were largely only useful as supplemental light.
There is absolutely no question that there are numerous models of modern LED's that are capable of very successfully supporting any light dependent organism that we are aware of. Unfortunately price is still the gatekeeper, but that is changing. Currently, most LED fixtures that most of us consider to be affordable are generally best used as supplemental lighting.
I currently use a combination of LED's and T5/T8's in my Zoa grow out tanks. The two biggest mistakes I see in most peoples zoa tank is the light intensity being far to high and failing to understand that zoas/palys vary a lot from one species to the next in their requirements.
Just a note in closing.
I've bought entire collections, on numerous occasions, because they were failing and the collector wanted to recoup some of their investment. The only thing wrong with their setup was too much light. The last one was a multi $1000 dollar fully computerized setup devoted to collectible zoa/palys. It had a 48 inch 8 bulb ATI T5HO fixture populated with ATI and Geismann bulbs hanging 24 inches over a 12 inch deep frag tank. Everything he owned was well into the final stages of dying and I bought it all with out any hesitation.
There are no blanket answers, there never was...
