Took me a while to find light data I gathered while diving off Kailua-Kona coast. Probably raises more questions than it answers...
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10 year system.
5 years on halide, 5 years on LED.
Just needed corals like those to make a nice pic out of the demo. (I have discount corals...popular back in the 1990's – my feeling is that nobody cares how you grow them one way or the other. I like em, but I guess I'm old.
Good feedback - love it!I've been in this hobby for close to 20 years. Back in the day we used 400 watt MH augmented with 110 watt VHO. The results were great but the heat and electricity was an added cost and complication.
That said, I have yet to see a mature SPS tank with what one might call moderate lighting...Less than a 250 watt MH Equivalent... The Ecotech Radion is roughly a 250 watt MH Replacement. If you are looking for a 400 watt MH LED replacement please check us out.
Most corals in nature are between 20 and 60 feet..Some Deeper... The Hawaii chart shows 700 PAR at 30 feet. Photohinibition is between 350 and 550 PAR depending on species. For SPS PAR above this results in desirable pigments to reflect the excessive light. Go deeper and there is less need for these pigments, coral are very adaptable to different intensities.
Over the last couple of years I've noticed a trend in using weak LED lights...Hardcore T5 users still have good results with 6 to 8 T5s over a tank less than 24" deep.
Here is a pic of a LED only tank. PAR is equivalent to a 400 watt MH and some...
Personally I like to see at least 200 PAR on the sand bed...Sanjay recommends a minimum of 100 with higher light corals closer to the top. My Red Carpet Anemone enjoys 270 PAR on a 30" Deep Tank, Clams are happy as well.
One must consider the future and as a coral grows...Especially SPS as they tend to shade our lights. Having more allows the extra light to be reflected thus providing light to remote shaded areas as in their natural environment.
I've used both PAR Meters and Lux Meters and have found both valuable when changing lights... Generally but not specifically a Lux Meter will have close to a linear relationship to a PAR Meter if you are concerned about burning corals. The errors in meters are generally 10% but can be as high as 20% so dial back and acclimate slowly.
Just some food for thought.
Cheers
Thanks! I should note that these measurements were made at noon, give or take a few minutes. Getting them required some effort (other than the normal routine of preparing for a dive and testing) since clouds roll off Hualalai volcano towards the ocean at almost the same time every day (usually around noon as luck would have it.) As you probably know, Kona is noted for its exceptionally clear water, with vis often at 100 feet or more (me, being a coral nerd, would say the water is classified as a Jerlov Ocean Type I.) Many reefs are growing in waters with considerably less light penetration. I have data from a dive at noon on a cloudy day. What did I do with that file???Well, it answers a lot (A LOT).
But what kind of environment (relatively speaking) is Kailua-Kona for corals?
What does that curve look like on an overcast day?
What does that range of samples look like from Palau? Jakarta? Bahamas?
Lots of answers, but lots of questions too.
Great info does that!
I've measured PAR only in some of the clearest waters in the world (off the Kona coast, west side of the Big Island of Hawaii.) So, yes, you are correct. Many are found in waters that aren't that clear. In the Kona waters, many corals are found in the shallows, but grow only in shaded areas, or fair poorly if they are exposed. I think PAR values of 100 to 300 micromole/m2/sec are sufficient for the majority of corals.
I actually think it's because you pretty much are forced to set it and forget it (no dimmer , no spectrum choices) , and most corals will adapt to to more light than less with poor spectrum.
A guy I know wrote some pretty good stuff on this too.
