Pictures worth a thousand words.
I like this project. But really did not clarify to much since the 2 tanks had issues. Also like the guy stated he only has 1 brick of led when he should have 2. As for the halides he has what is needed fully. This is worth waiting 6-12 months to see the real difference in the growth.
to make a more valid experiment, he could set up two identical small satellite tanks running off the main tank sump. one with a halide over it, and one with a comparable LED fixture. then make two frags from the same mother colony as similar in size and mounting as possible and place in eact tank. of course the frag coming from the MH main tank will be more adapted at first than the one going under LED. so a longer test time would make some difference. other than light source, the two tanks would be on the same water quality and flows and sand and depth. all things controlled except the lighting difference.
+1
If LED’s are shown to be only slightly more effective than MH than the energy savings are negated by the high sticker tag when you are considering which one to get. Also they say they can last up to 7 years but how many people have had them 7 years yet? If diode’s fail here and there then that increases the cost as well as if you are supposed to upgrade the hardware sooner than 7 years (i.e. if they come out with better pucks ect.)
I’ll stick with my T5’s for now.
all i can say is i LOVE my leds. only time will tell just how good the leds really are.
+1 to brett. i have 2 mixed reef mostly sps tanks with leds one for 15 months and the other for 4 months. love them and wouldnt thing of going back
+2 mine are one of the best things i ever got, 8 months in.
+1 with Tim. I’m still not sold on LEDs yet. I’v look all over the web for LED and MH comparison and didn’t find any that can proof LED will grow SPS better than MH. Sure it might save some money in the long run by using LEDs, but for the growth and well being of keeping SPS with MH is by far grater than to just keeping them alive by using LEDs.
[quote=“kaptken, post:3, topic:4389”]
to make a more valid experiment, he could set up two identical small satellite tanks running off the main tank sump. one with a halide over it, and one with a comparable LED fixture. then make two frags from the same mother colony as similar in size and mounting as possible and place in eact tank. of course the frag coming from the MH main tank will be more adapted at first than the one going under LED. so a longer test time would make some difference. other than light source, the two tanks would be on the same water quality and flows and sand and depth. all things controlled except the lighting difference. [/quote]
Here is the setup of fat jack.
He makes it sound like the tanks are hooked together
I have to say that takings a coral from a tank with 800 watts of halide and putting it under the 1 brick led fixture will probable take more then 8 weeks to acclimate
That’s getting closer to a good experiment. but still no controls on light intesity or spectrum between tanks. I would use two satellite tanks off the sump, and an LED on one and as close to the same lumen output MH on the other. then adjust them up and down to get similar PAR at the level you place the coral frags.
I think LEDs are great. although the most practical ones put out about the same lumens per watt as T5 or MH, they are more focused. so they probably put more light on the corals. What I have noticed is that all LEDs produce blue in the 445-470nm range which feeds chlorophyl B just fine. But they have nearly none in the 400-440nm range which feeds chlorophyl A. Coincidentally, MH lamps above 12K are similar with a big peak at 453 nm and almost none at 420nm. since i switched my frag tank HQIs to Phoenix 14Ks i also changed my supplemental T5 actinics to ATI 420nm actinic blue. great colors and growth on the acros .
when i used 10K icecap HQIs I supplelmented them with 450 nm ATI Blue Plus T5 actinics, and also got good colors. Most 10K MH bulbs have their major peak at 420 nm and little at 450nm. I believe either combo is good because they feed both chlorophyls.
You can plot spectral charts from Sanjay’s test data base. it looks like he has had the chart problem straightened out now. if you use the COMPARE LAMPS tab, you can overlay many bulbs to see that they have the same peaks when they are similar Kelvin. the watts just determines how high the peaks are. or energy.
So i would augment LED lighting with 420 nm actinic T5s, just like high kelvin MH lighting. Paint by the numbers. Corals can adapt to one blue or the other, but why not have both?
His comments on modularity of LEDs is a very good point to consider when buying them.
There are now a few out there selling what they call Violet Led’s that indeed peek in the 420nm range.
can you show me one. most i see are 350-400nm UV for black light and medical use. but we use shield glass on MH bulbs to block that range of UV.
but wait a sec. its been a while since i looked, and here is one company making a 420nm half amp led.
http://tech-led.com/High_Power_Illuminators.shtml
first one ive seen. Still, all the Reef LED lights on the market use blue or royal blue LEDs in the 450-470 range. I try to find blue for these two chlorophyl usage peaks. it doesnt matter to them what the source is.
http://www.ledssuperbright.com/3w-ultra-bright-uv-violet-led-p-187
BoostLED MU series have Violet blubs which can get close to 420nm
http://www.boostled.com/collections/frontpage
Orphek has some Violet bulbs in some of their PAR38/30 bulbs
Pretty close. I dug out my notes and found that the true absolute absorption peak for chlorophyl A is at 430 nm. which is why our old 420 actinic bulbs work just fine. because they peak at 420 but have a wider spread above and below that point which is still very near the peak at 430. But going below 400nm on UV gets into the danger zone for UV burn. so thats good to see they have found some low 400 doping for the LEDs. up till now it was the holy grail.
So looking at the chlorophyl chart, the old 420 blue lamps covers both A and B pretty good, high on the curve where they both cross at about 430-440. but a royal blue 450-470 LED will only grow type B. I still think supplying both blue ranges would be the best thing for a healthy coral. oh, and according to my notes, chlorophyl A Fluoresces at 410nm. hmmmm??