Coral color with led vs halides?

We have to STOP assuming that we can just randomly say "MH Vs. LEDs". As already hinted by some folks in this thread, you can't just quantify "MH" and "LEDs" so that you can compare them. Even in the general sense, it doesn't work well. Crap@$$ LED units that use chintzy no-name 1-watt LEDs with a grossly over-exaggerated blue K-temp isn't going to compare very well with a reasonably made halide fixture and quality bulb.

A well-made LED rig using the right color combinations can easily give the same useful light (and, I argue, all the color and MORE) of a halide of twice the wattage in even the best reflector. But these "well-made LED rigs" are so far and few between that it's nearly impossible to find them except in DIY rigs of people who have done some research.


The problem with bad colors under these LED rigs has much less to do with the inherent qualities of LEDs in general, and much more to do with the color combinations used by these units, and the naivete of the users who burn the holy hell out of their corals with them.


Problem #1 with LED rigs-- Manufactureres are using too high of a K-temp white LED. When you see a rig using a handful of cool whites (~6500-8000K) and a TON of blues, you can expect color to suffer. Cool whites can look good but they need to be in a 1:1 ratio with blues... NOT a 1:2.



Problem #2 with LED rigs-- Manufacturers using stupid-high K temp whites-- some use 10,000K and 20,000K whites, and then a ton of blues. Obviously this is going to be even less appealing to the eye than Problem #1.


Problem #3 with LED rigs--- Manufacturers are using too many "cool blue" or "normal blue" LEDs rather than royal blue. It's good to have a few "cool blue" (465-480nm).... but some units like the AI-SOL BLU have way, way too many of them. Makes the tank look like a whole army of drunk smurfs pissed in your tank. There is a 240g tank, locally, that has 4 SOL-BLU units over it, and I do not like the color at all. It's windex-galore.


Problem #4 with LED rigs--- Users aren't starting them on a VERY low light output. It doesn't take much visible light shock from LEDs to kill the ever-loving heck out of SPS and LPS corals. We've seen this over and over and over and over.



The solution I recommend is for people to focus on DIY rigs, and the handful of rigs that can be bought with the following "basic" LED combinations.

ONE 4200K neutral-white LED to every TWO royal blues. There is room for variance here (3800K to 5500K), and your dimmer knobs make all the difference in the world. I've seen this combo over and over, and it works gorgeous. I use a similar combo on my own reef, which is admittedly small (see my sig), but I'm also building a 45g cube with the same combo, and I have all the confidence in the world that it will look fantastic.

If you disagree with me on this (which I welcome), then please find a tank with this color ratio on it, using a name-brand LED (Cree, Rebel, etc) and then come back and tell us what you saw. Sure, you will find some corals that do not look right under it, but the same thing happens under even the most lauded halides and T5s.

Agreeing with Thatgrimguy. But also adding this; switching your lights can cause chain reactions in your tank's stability that also slows growth.

I've seen the following scenario happen several times, and LEDs get the blame, when it's really user-impatience causing the problem.


1) User buys LEDs, removes his time-tested halides which his tank is fully accustomed to.

2) User forgets that the corals will need time for adjustment to the new light source, and continues to feed his tank and dose calcium/alk at the same levels.

3) Corals are either photoinhibted (light shock) from the high intensity of the new LEDs...... or......... if the user was smart enough to turn the LEDs way down first, the corals are just getting less light for the moment, and slowed growth.

4) Nutrient (nitrogen and phosphorus) levels in the water rise, as do calcium and alkalinity.

5) Corals respond to these swings (esp. phosphorus and alkalinity) by growing even slower. Color suffers also.

6) User blames the LEDs, doesn't give them sufficient time to adjust, and then sells LEDs and returns to the "glory days" of halides.

100% agreed, which you can see above. Just to elaborate. Every LED rig is different in spectral output capabilities, number and quality of LEDs, optic angle, LED density and spacing, and so forth.

Halide rigs are, admittedly, a bit simpler. One bulb, one reflector, and one ballast. Three variables that we can actually halfway predict within a realm of certainty (mostly thanks to Sanjay!!!).

 

First of all, I'd like to thank everyone for putting in there opinions on this, it helping me a lot.

Second, redfishsc, I'm sure your right on a lot of what your saying, but LEDs have gone a long way from 1 watt with a crazy amount of blue. The fixture I have is a Cree 3w led with cool whites and royal blues. I do think there is a problem with LEDs having a whopping two colors on a tank, but that's where supplemental lighting comes in. Another problem is the horrible color rendition of Cree LEDs. Some of those less known LEDs that are less powerful are actually better, especially for supplemental lighting because they have a better temperature and color ratio. The whites in bridgelux diodes have a better yellow to red ratio than the crees from what I've heard. I'm going to be doing a strip of led with ocean white color LEDs, which have 420nm blue, 660 red, and 475 cyan. They are a 3 diode palette. Then I'll add some uv ( not actual uv, just 405nm violet) with green, neutral white, and warm white. That should give me the most out of my spectrum, making sps color up more, and hopefully tone down the royal blues in the tank. As you said, they do look like drunk smurfs in there lol.

You brought up a great point that I haven't really thought of, photo inhibition. That would make a lot of sense for most, but I havent seen any decline of growth in my tank, probably because my lights are dimmable and I started at about 10%. I have just seen lack of color, which I'm sure is because of the lack of spectrum.

 

You should look at all the research he did on led spectrographs. It will help with this.

http://www.3reef.com/forums/led-aqu...larger-bridgelux-few-chinese-leds-129292.html

 

Oh thank you, I'll be reading this!

 

Im not sure of I'm reading the pictures right, but it seems to be that bridgelux LEDs are good for what I was needing. I can definitely see the small spike of blue in Cree LEDs, so that would make sense. The graphs are great, I really appreciate it, thanks.

So for LEDs to be efficient for sps, we need the most color out of the spectrum, which means it has to be DIY because no one has a fixture out with everything we need? Also, how would a combination of the two types of lighting be on a tank, mh and led? Would it be too powerful? I think a metal halide tank with supplemental LEDs would be really cool..

 

http://www.youtube.com/watch?v=jgkPxWogmEg&feature=youtube_gdata_player

Here's a good video of the differences. I wish there were more pics though..

 

Many many people combine different types of lighting. One of my very favorites is a quality metal halide set up with blue led supplementation. You get all the fun dusk dawn, with the ease of metal halide and it's associated benefits.

There are some really awesome led/t5 combos as well. And t5/vho and metal halide are very common, probably the most common set up in fact.


So, on the led vs spectrum question. We don't exactly know what we need yet. So we are trying to figure out is what we have and what something proven has. So try comparing spectrographs like the one I posted to MH spectrographs that Dr. Sanjay does and try to mimic the peaks in popular MH bulbs. Basically trying to replicate something we know works.

Right now, the research is still being done. Metal halide has the benefit of a decade of testing that we are just starting on LED. So we don't know the best combination yet. But an increasing number of hobbyists are becoming convinced it takes more than just white and blue/royal blue.

 

I would add all the leds they sell right now for a full spectrum, but I've heard it looks ugly because try penetrate so well. What I'm thinking right now is add supplemental LEDs, then build a canopy and add mh, t5, or pc. I dont think I can find a t5 or mh small enough though. I want even distribution so I think I would need two of whatever fixture it is.

 

This is for your 30g right? I honestly think you should do a DIY full Led system. As the months pass you can go back in and add more LEDs to complete your spectrum. Also keep in mind you have full control of what your tank will look like (Using dimmable drivers). I added Cyan and UV a month later and it didn't make anything look weird at all.

T5s and MH are great for a larger tank but I think DIY LEDs are perfect for smaller and even larger tanks. I know there will be people out there that feel differently but I truly love my LED setup. I don't think I could have matched it with a MH or T5 setup..

One thing you will learn in this hobby, there are about 10 different ways to achieve the same results. I love gathering all 10 different ways and meshing them together to make it "My way".

 

Yes its the thirty. Unfortunately I would be very mad at myself if I made a full DIY build and didn't have a need for the led unit anymore. I might make more strips in the future to offset the cost and make it more modular.

I Think this might be one of the most compelling subjects in the hobby as of now. I love how your tank looks and because of the similarities of our tanks, I'll be doing the led as you said. I can always add additional light in the future.