Firstly the benefits from non-industrial strength LEDlighting are astounding!
Recently there has been talk of some thing the aandtsociety has known for many years,corals do not like UVR,ultra violetradiation,(ultraviolet light).
In fact we humans designed a sunscreen around what the corals use to protect them selves from the suns harm full radiation that so many marine hobbyists and supposedly knowledgeable people educated in marine sciences still to this day value the useless UVR emitting resistance lighting as is metal halide and tube lighting compared to LEDs.
The production of the corals protective coating for harmfull lighting takes so much out of corals!
The LED technology has been very adequate for all corals and all reef aquarium life forms since the mid 2000s!
LEDs can not be tested for PAR affectively as resistance lighting can,it does not emit anywhere near the UVR resistance lighting does,so a weak PAR rating from LEDs means nothing,the R of PAR is radiation and LEDs emit near none!
Also the need for the use of controllers for the LEDs is a fallacy as well,the corals in your aquarium do not need gradual sun rise and sunsets, also copying moonlight and so on and so on, all a waste of time,unless you have money to burn and like toys!
The corals exist fine with lights on, lights off,just keep it the same time each day!
Though it should be remembered that fish do far better when they have a night light to reduce stress.
Fish do not sleep,they try to remain still and stress as to what will possibly eat them as many life forms come out at night that touch them accounting for most fish ending up on the carpet!
The length of time the coral algae clades have the lights colour spectrum for the excitation affects to photosynthesise from is what has to be applied for coral gorwth.
The weaker the light the longer it has to be on to allow the corals algae to feed on the corals waste and other substances in the water
Kelvins,the difference in lighting as with the Kelvin rating is a somewhat over rated notion as well.
One to two watt LEDs with 14 to 16000 Kelvin rating is right up there compared to the old xr-e that is rated at 6 to 8000 kelvin and not much better for the xp and xm range as well, but at depths in the aquarium the 3watt diode pushed the smaller Kelvin rating much deeper and actually provides a higher Kelvin rating to depths in the aquarium.
Plus the degree of light is essential when applying LEDs as well, normally LEDs are rated at 180 degrees and the best degree of the beam of light from these is from a 60 degree diode.
The diode originally with the 60 degree built in is better then altering it your self later with a reflector on each diode.
The xr-e diode 90 watt with 90 degree diode fittings we had made in china for $162 Aus each with 3 computer fans on board were we thought,rated at 6 to 8000 K and when they were tested they went above 17000 and the same lumins as the 3.30 pm pure sunlight???
The rating we looked at on the net was for 180 degree diodes, that was most likely the difference in our results.
This is how a 2 foot tank can perform with natural filtration,no skimmers as such and especially my out dated 3 watt xr-e diode LED lights.
This is it as of last week, it gets better and better than the ocean it self.
LEDS work very nicely, especially with the NWMS that does far to much to describe, I will just leave this at,LEDs run cold, produce nearly no heat at all, last for up to 10 years at full aquarium strength, grow every thing in the reef and freshwater aquariums and use very little electricity and are simply astounding.