I have seen limited successes with LED lighting. They looked awesome, but none of them have matured beyond more than maybe two years and lacked any sensitive SPS corals and clams, and so aren't really all that conclusive. I still assume it is lacking in serious ways, and incapable of sustaining the more demanding organisms. My logic is as follows:
Marijuana cultivation is a million times more popular and profitable than coral cultivation. The lighting issues for horticulture (heat, PAR/watt, spectrum, bulb life, and operating cost) are the same as those that weigh us reef keepers down. As there is more profit to be had, the likelihood of product innovations is much higher in horticulture. There are a ton of people working on LED lighting systems for marijuana, with countless dollars being poured into the research. There are a ton of people growing with LED, but the product they are producing is crap, with low yields, low cannabinoid content, and poor taste. The reefkeeping LED technology is at the same position. It can work for some stuff, but not as well as better developed technologies.
It took 150 years of research to get a 20K metal halide bulb. LEDs have only been around for like 30.
In short, when they work well, everyone will be using them.
