Anyone Thinking of Dumping LEDS and going back to Halides

[newenglandreef]

First, light from this part of the spectrum does excite pigments within the corals, bringing a layer of color to the tank just by showing the color.

But where is it said that only the 420nm excites pigments (all pigments or just some?)? I don't understand how we can say, today, what 420nm affects specifically.

Secondly, light in the ~420nm range actually corresponds to one of chlorophyl A's absorbance peaks, so its useful light to the coral.

Useful in what manner? That's another issue I don't understand. As far as we know...and, I think, all we know, is that corals get their food from light (partially). So by saying that it isn't getting 420nm, does that mean it's not getting enough food? Because, clearly, LED's throw out enough PUR--I don't think that's disputed. What exactly is the coral being deprived of from the lack of 420nm?

 

[sirreal63]

I don't think it is just the 400 to 420 area, if you look at the spectral plots of a Radium you will see it has a lack of 400 to 430 and has its blue peak about 450, but then a 10k bulb, which has a strong 420 peak usually grows sps faster than a 20k bulb, but there is more to the peaks and valleys than just the 400 to 420 area. I think it is more than just the spectrum but where the peaks in that spectrum come in. Most of us expect the more enhanced fixtures like the Mitra, PacSun and a few others to do better with coloration than the blue, royal blue and white fixtures, and early reports seem to support this, of course time will tell but those 400 to 420 areas are important..

 

[bhazard451]

I disagree, 50 or 100 of the same leds in a 2" square with the same optics is going to be much higher par

with the 1-3w leds you have to spread out the leds, you simply cannot match the par because you cannot physically get them that close together

I too have a par meter

This would be the case if those multi-chips were using Cree or Luxeon leds, but they are not. They are using Epistar leds that are about 30% less efficient. In fact, those multichips are using the same 3w leds that you don't seem to like, just in a smaller footprint. You could use 10 3-up Cree star leds in a slightly larger footprint to achieve the same results, with less heat generated. Those multichips require massive amounts of active cooling not to burn up, such as a PC/VGA cooler, which aren't practical.

Those chips also do not have a wide range of selectable spectrum available. You are stuck with one color or two colors (hybrid) to choose from, neither of which are very good. The five channel one you have only comes in one layout, and it also has wide gaps in spectrum, despite what certain individuals tell you about them. In my opinion, they aren't a very good implementation.

Until more individuals with wide spectrum fixtures post experiences and growth pics from their Maxspect Razor, GHL Mitra, DIY setups, and upcoming Radion Pro, there isn't enough data to suggest leds are truly better than MH/T5 at this point.

 

[newenglandreef]

I don't think it is just the 400 to 420 area, if you look at the spectral plots of a Radium you will see it has a lack of 400 to 430 and has its blue peak about 450, but then a 10k bulb, which has a strong 420 peak usually grows sps faster than a 20k bulb, but there is more to the peaks and valleys than just the 400 to 420 area. I think it is more than just the spectrum but where the peaks in that spectrum come in. Most of us expect the more enhanced fixtures like the Mitra, PacSun and a few others to do better with coloration than the blue, royal blue and white fixtures, and early reports seem to support this, of course time will tell but those 400 to 420 areas are important..

If it's not just about the 420nm--and more about the spectral variation, then wouldn't it make sense what others are saying about corals having to adjust to the new spectrum under LED's (as with the switch to/from MH and T5)? I just don't understand what MH and T5 are giving to corals that LED's are depriving--especially if the 420 nm isn't significant. I'm not sure who can say that with the state of the science today.

 

[biecacka]

Very interesting thread. I switched to the nova A4 LEDs from china. I like them but can't say they color is better than t5's or MH. I have a softy lps tank so I'm hoping they will work.
Corey

 

[rtparty]

If it's not just about the 420nm--and more about the spectral variation, then wouldn't it make sense what others are saying about corals having to adjust to the new spectrum under LED's (as with the switch to/from MH and T5)? I just don't understand what MH and T5 are giving to corals that LED's are depriving--especially if the 420 nm isn't significant. I'm not sure who can say that with the state of the science today.

420nm is very significant. The lack of light below the 430ish area has been a major problem with LEDs.

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[mhucasey]

But where is it said that only the 420nm excites pigments (all pigments or just some?)? I don't understand how we can say, today, what 420nm affects specifically.

See the following graph for absorbances:

from the article in a series about coral coloration, specifically flourescence:

http://www.advancedaquarist.com/2006/9/aafeature

Useful in what manner? That's another issue I don't understand. As far as we know...and, I think, all we know, is that corals get their food from light (partially). So by saying that it isn't getting 420nm, does that mean it's not getting enough food? Because, clearly, LED's throw out enough PUR--I don't think that's disputed. What exactly is the coral being deprived of from the lack of 420nm?

When I say useful I mean that the light is usable for photosynthesis - not just for looks.
Corals probably get more than enough light for photosynthesis, that is true - especially on the top surfaces of the corals. Many studies have shown corals to undergo photoinhibition with relatively small amounts of light. Adding light that more closely corresponds to the exact peak that chlorophyl requires seems like overkill from that perspective.

So why is it that the best and fastest growing reef aquariums typically have massive amounts of light over them(and lots down in the lower 400nm)?
I think there is a lot we are still learning when it comes to calcification in corals - light certainly plays a part in calcification not just photosynthesis:
http://www.jstor.org/discover/10.23...2&uid=70&uid=4&uid=3739256&sid=21101397182813

 

[reefgeezer]

Until more individuals with wide spectrum fixtures post experiences and growth pics from their Maxspect Razor, GHL Mitra, DIY setups, and upcoming Radion Pro, there isn't enough data to suggest leds are truly better than MH/T5 at this point.

I don't think LED's are "better". I think they are roughly equivalent. I use LEDs. My tank is not photo worthy, but I know it's not the LEDs but my husbandry practices that are to blame. Seems to me that RC has had many threads showing truly amazing SPS tanks that are running on 100% LED lighting of many different specifications.

 

[mhucasey]

Unexpected effect of switching to T5s - my pH has risen significantly. In the past I have had chronically low ph which would rise to maybe 8.1 at the peak of the light output and quickly drop after dark. I blamed this on carbon dosing and the alkalinity value of ~8 that I was running. I've tried adding kalkwasser to the topoff and would see short term effects on the ph, but keeping the pH above 8.1 was not possible with the alk value drifting up(sometimes unexpectedly fast).

I switched to T5s last Saturday, the pH has been higher and higher each day.
Last night when lights went out pH was 8.35, and was still above 8.3 at midnight. Alk value is 7.8 with the same dosing. I'm actually using more alk than before if you consider I'm still adding kalkwasser to the topoff and the alk value is actually dropping....

 

[djkms]

Unexpected effect of switching to T5s - my pH has risen significantly. In the past I have had chronically low ph which would rise to maybe 8.1 at the peak of the light output and quickly drop after dark. I blamed this on carbon dosing and the alkalinity value of ~8 that I was running. I've tried adding kalkwasser to the topoff and would see short term effects on the ph, but keeping the pH above 8.1 was not possible with the alk value drifting up(sometimes unexpectedly fast).

I switched to T5s last Saturday, the pH has been higher and higher each day.
Last night when lights went out pH was 8.35, and was still above 8.3 at midnight. Alk value is 7.8 with the same dosing. I'm actually using more alk than before if you consider I'm still adding kalkwasser to the topoff and the alk value is actually dropping....

Interesting observation. My pH with LED's was always around 7.9-8.1 peak. After being on Halides for a few months my pH is now between 8.1-8.35 peak. I thought my pH probe was going bad but now I am not so sure!

 

[megadeth72]

You could use 10 3-up Cree star leds in a slightly larger footprint to achieve the same results

sorry, 10 3w crees does NOT compare to 50 3w bridgelux in the same space, and I'm not sure how you could get 10 pucks to fit into that size constraint for starters, and 10 simply cant compete with 50

yes cree might be a little bit more efficient, but until there are multichip cree's I'm simply not going to run them again

on a "taste" aspect, the big array of single led's look too much like vho/t5 for me, I dont like the light they produce, cree/bridgelux any 1 or 3w led spread out on a heatsink is not something I like at all, it's not a point source like halide or a multichip led.

multichips require a real active heat solution, not a slab of aluminum that seems popular, that said my 3w chunk of aluminum gets hot too without a fan

if I had to choose between halide and a 3w cree single chip setup, I would choose halide.
If I had to choose between halide and a multichip, I would choose the mulitchip

any other light vs halide, I would choose halide, ie against t5 or vho

 

[mos90]

when i started my 125g reef about 2 years ago i had 2-250 phoenix mh's with t5s. corals were doing good of course i need to try new things. i switched to 4-ai-sol blues. never did like the corals colors or get the intensity set correctly. ended up losing a handful of sps and a brain coral. i switched to t5's but i still didnt care for them as much a the mh's.

the 125 no longer exists but all the coral i have left is in a 75g holding tank with 2-250w radiums with 420 actinics. all the coral but my flowerpot coral is doing great.

my 300 build will have 2-250w 14k hamiltons and 1 400w radium in the middle with 420 actinics . no more leds for me for a while.

 

[AcroporAddict]

Unexpected effect of switching to T5s - my pH has risen significantly. In the past I have had chronically low ph which would rise to maybe 8.1 at the peak of the light output and quickly drop after dark. I blamed this on carbon dosing and the alkalinity value of ~8 that I was running. I've tried adding kalkwasser to the topoff and would see short term effects on the ph, but keeping the pH above 8.1 was not possible with the alk value drifting up(sometimes unexpectedly fast).

I switched to T5s last Saturday, the pH has been higher and higher each day.
Last night when lights went out pH was 8.35, and was still above 8.3 at midnight. Alk value is 7.8 with the same dosing. I'm actually using more alk than before if you consider I'm still adding kalkwasser to the topoff and the alk value is actually dropping....

Maybe your probe needs to be calibrated?

 

[kupadupapupa]

I think the issue with people not liking leds is because they're using the fixtures that use the measly 3 watt led's in them, not to mention most of those fixtures only have 20-30 of those little 3 watt leds built in.

I've seen most of them in person and they are just too way to dim to the eye so I built a fixture using 30 watt leds and couldn't be happier, they are brighter then my 250 watt halides and grow a variety of corals very nicely. The main reason why I am so happy with my Leds is because my monthly bill is now 100 a month less, I was shocked how much I was paying to run those Mh's because i've had no idea.

 

[rtparty]

I think the issue with people not liking leds is because they're using the fixtures that use the measly 3 watt led's in them, not to mention most of those fixtures only have 20-30 of those little 3 watt leds built in.

I've seen most of them in person and they are just too way to dim to the eye so I built a fixture using 30 watt leds and couldn't be happier, they are brighter then my 250 watt halides and grow a variety of corals very nicely. The main reason why I am so happy with my Leds is because my monthly bill is now 100 a month less, I was shocked how much I was paying to run those Mh's because i've had no idea.

Yes, trusting your eyes to how ''bright'' a light source is is a great idea. Nothing could possibly go wrong there.....


I suggest you study PAR, PAR meters and how a human eye works.


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[megadeth72]

I have a par meter and I agree 100 % with what he said, optics help a lot, but still cant match multichip setups

 

[kupadupapupa]

Yes, trusting your eyes to how ''bright'' a light source is is a great idea. Nothing could possibly go wrong there.....


I suggest you study PAR, PAR meters and how a human eye works.


Sent from my SCH-I535 using Tapatalk 2

I really hope you're not serious guy. It doesn't take a par meter to realize if i'm looking into a dark box filled with water. After all, don't we set up a fish tank to make it pleasing to OUR eyes?

 

[nanolover80]

Hello, i was just getting into LED's and i think they would be grat over my nano and pico tanks, what do you think? Nano is a AGA 5 gallon and will have 30W white LED's.

The Pico is a 2.5 gallon tanks and will have either 10W or 20W Led's depending on how bright i think they are. Do you think this is a good idea?

Also i will be setting up 3 other tanks, a 10 gallon AGA as a quarantine tank, a 29 gallon AGA and of course my old 55 gallon AGA. I will be using Metal Halides on the 55 gallon will have 2 400W 20K's, not sure what to put on the 29 or the 10 gallon.

So let me know what you think

BTW, all i have read on here and elsewhere says that Halides are still the best whille LED's are coming along nicely.

 

[James77]

I really hope you're not serious guy. It doesn't take a par meter to realize if i'm looking into a dark box filled with water. After all, don't we set up a fish tank to make it pleasing to OUR eyes?

But it does take a PAR meter to know how much PAR you are getting. If you packed on enough LEDs to be as bright as some halide setups, you could scorch the corals.

 

[Wolfgang]

Actually, it is that Spectrum Missing from LED's that is the Problem!
See Here:http://www.advancedaquarist.com/201...ider&utm_medium=slider&utm_campaign=clickthru


-Wolfgang