Radium vrs Radion

[vanpire]

Why not run the AB+ spectrum on the Ecotech that is claimed to be the best for SPS corals? We already know the Radium is tuned for that out of the box. What reflector are you using for the halide? I like this experiment. How about matching wattage outputs for this?

I think this is a great idea. You should choose the setting that is recommended as best by the manufacturer. It should take out the issue of user error trying to adjust what you think the "correct 20K" spectrum should be for LED. And 20K spectrum might not be the best for growing SPS with LED anyway.

 

[spiraling]

I would also suggest more than one frag per tank (either same type or different). Several frags in each tank will help reduce the variability caused by cutting and gluing the pieces.

 

[Davy Jones]

Since you are just measuring weight for growth I am assuming coloration will not play a valuable role in this experiment?

 

[Centerline]

Plumbing the two experimental tanks into a common sump is a smart idea - you can rule water chemistry values out of the equation. There is a lot to be learned from experiments such as these and I'd be interested in hearing the results. It sounds like you want to use weight as the metric for coral growth. There are some very good (and inexpensive) digital pocket balances that compare very well to the $1,500 lab balance I have. Let me know if you need a link. The real issue I see is comparing one 20K lamp (metal halide) to another 20K source (LEDs.) As you probably know, there are many mixtures of light that can arrive at a given K rating. If you matched K from one light source to another, an analysis of the light would show different spectral characteristics. This is not to say that the results are without value - just state what settings you used on the LEDs when comparing to the halide lamp. If you really, really want to get into this, get a spectrometer that has the ability to measure the spectral signatures and generate a K rating. With the Ocean Optics specs, this requires calibration to a known (NIST) light source and will set you back around $6,000. So, I would recommend simply defining the LED settings and visually matching the spectra. Other issues. I found that calcareous and other algae growths on the ceramic coral plugs could not be removed successfully without impacting weight measurements, so the experiments will be limited to perhaps 60 (maybe 90) day timeframe. Water motion can and will impact growth rates so used exactly the same pumps and pump/coral positions in each tank. Use as many frags as possible (I used 10 per light source experiment.) Having been through several sets of these types of experiments I think I can assist you with further questions you might have. Just let me know, and best of luck!

So I would very much indeed like to make as accurate of a comparison as possible, is it worth 6k to me? Probably not. Maybe a call to Echotech could get me the information before I start shelling out cash. Using their 20k setting looks nothing like a Radium so I'm not terribly confident that based on a visual comparison I'll have results that can be taken seriously.

With respect to using as many frags as possible, great idea. I have a friend who runs our LFS who already volunteered to order frags from ORA for me and sell them at cost so maybe 6 or so frag per tank would be doable. The ORA plugs may make a better platform than ceramics considering your comments with regards to algae removal.

Water movement will not be an issue. I'll likely use a MP10 in each tank, I have a couple of gyrers as well but it seems like it could be overkill. But maybe not.

Its funny that you mentioned ALK as I was recently called "old fashioned" for running my ALK at 12 on an SPS tank. I have always had great results with RCP salt as long as I could keep the PH in the tank above 8. I refereed them to your article on ALK and water movement. You can lead a horse to water....

 

[Centerline]

Since you are just measuring weight for growth I am assuming coloration will not play a valuable role in this experiment?

No, Radiums produce some very unique coloration at times and assuming I may have to settle for a 20k standard on the Radions I have no idea where the coloration will end up. It will be interesting though.

 

[Centerline]

I would also suggest more than one frag per tank (either same type or different). Several frags in each tank will help reduce the variability caused by cutting and gluing the pieces.

I believe that I'm going to use frags straight from ORA in order to remove frag damage from the equation.

 

[Centerline]

I think this is a great idea!!
Maybe you should get a brand new Radium bulb with the best ballast that bulb would need for it's best performance and the best metal halide fixture/reflector. Each bulb also needs the right type of ballast recommended to keep spectrum, intensity and PAR.
You will probably need a cooler for this experiment and a heater to keep temp stable.
I think stability of the water params will be a must and you should do your best to achieve that although they will be in the same system.
Get the LED fixture and set for the best of what would be from the manufacturer as 20K.
Like Dana said, the chemistry will be out of the question and that's what matters the most, but I do hope you keep them stable.

Don't forget what Dana said about the water motion!!!
The water motion alone could turn the whole thing up side down and the results would be false!!!
Te corals need to receive the same amount of water motion from the same pumps and positions..

If you do the PAR readings, Lux readings and Spectrum readings, great! Dana will help and he will be very excited!!

But the recommendation from the manufacturer of the LEDs for the same 20K spectrum should be the way to go. They are the best people to talk to. Call them... The halide has no problem with that. It's supposed to be already at it's best. Just get the best reflector and the right ballast for the best efficiency!!

The coral frags should be from the same mother colony, healed from cutting, placed on plugs at least 1 month under the same type of light, side by side, so they heal and grow in equal form, size and color first. Then they can be slowly adapted to the new lights for the experiment.

This is really great!
I hope this thread will have lots of LED and MH people tagging along together for the results...
Grandis.

Ya, I think you are absolutely correct about calling Ecotech. Stability should not be an issue as I have a couple of chillers, plenty of gear for water motion, heat, etc.

 

[Centerline]

I think this is a great idea. You should choose the setting that is recommended as best by the manufacturer. It should take out the issue of user error trying to adjust what you think the "correct 20K" spectrum should be for LED. And 20K spectrum might not be the best for growing SPS with LED anyway.

Agreed and that is why I want to match the actual k values of the Radium.

 

[spiraling]

Agreed and that is why I want to match the actual k values of the Radium.

So is the point of the experiment to determine if two different light sources emitting the same wavelengths and magnitude of light will perform the same? All you are going to prove is that the light spectrum of the sun will NEVER grow good corals

I would rather see the halide vs the AB+, but whatevs' its your experiment. ;Muted

 

[saltyfilmfolks]

Agreed and that is why I want to match the actual k values of the Radium.

Visually , what would you say is the difference between the two.

 

[saltyfilmfolks]

So is the point of the experiment to determine if two different light sources emitting the same wavelengths and magnitude of light will perform the same? All you are going to prove is that the light spectrum of the sun will NEVER grow good corals

I would rather see the halide vs the AB+, but whatevs' its your experiment. ;Muted

"Approximate" wavelengths would be more correct. The MH actually has more stuff in it on either end. And also it'll be interesting to see if the led can even actually do the same spectrum.

Clearly the leds 20k mix is already different than the MH just by a visual test.
Most do forget there's a lot of ways to make 20k or any other color.

 

[Centerline]

Visually , what would you say is the difference between the two.

Subjectively, Radiums have a very crisp white undertone. Not to say that the bulb lacks a nice bluish tint but it doesn't present the deep blue overtones of the Radion. The Radions have a hint of purple as well. The subtle color separations in corals also appear to have more stark and defined demarcations with Radiums. I assume this is due to the UV range of the Radium. My observations of the Radium is based on a 250 SE on an electronic selectawatt ballast (normal 250 / not hqi).

 

[saltyfilmfolks]

Subjectively, Radiums have a very crisp white undertone. Not to say that the bulb lacks a nice bluish tint but it doesn't present the deep blue overtones of the Radion. The Radions have a hint of purple as well. The subtle color separations in corals also appear to have more stark and defined demarcations with Radiums. I assume this is due to the UV range of the Radium. My observations of the Radium is based on a 250 SE on an electronic selectawatt ballast (normal 250 / not hqi).

Thank you. I do have a a 150w de radium w a Coralife fixture I ran for a while on my cube.

Interesting the led is bluer. The separation is understandable because it is after all a mulit point light and not a single source.

 

[Centerline]

So is the point of the experiment to determine if two different light sources emitting the same wavelengths and magnitude of light will perform the same? All you are going to prove is that the light spectrum of the sun will NEVER grow good corals

I would rather see the halide vs the AB+, but whatevs' its your experiment. ;Muted

Well I'm not opposed to AB vrs halide. I had some crazy fast growth on a Paletta tricolor using the AB program so I know it works well. But in this instance I plan on validating an assumption I have that if I can tune a Radion in to approximate a Radium then growth will be similar. However there are some technical properties of the Radions that may make this a little more complicated. Hot spots can be delta with by using a diffuser, par intensity differences between the different diodes can hopefully be handled by tweaking intensity (assuming my par meter can accurately read them). However, complete wavelength and magnitudes are not actually the same at all as MHs have discreet wavelength characteristics that LEDs avoid in full spectrum implementations.

 

[Centerline]

Thank you. I do have a a 150w de radium w a Coralife fixture I ran for a while on my cube.

Interesting the led is bluer. The separation is understandable because it is after all a mulit point light and not a single source.

A 400 on a magnetic ballast is a bluer... academic.

 

[Dana Riddle]

Not sure if you've seen this, but here goes:
http://www.advancedaquarist.com/2015/4/corals
Very interested in hearing your results!

 

[Centerline]

Not sure if you've seen this, but here goes:
http://www.advancedaquarist.com/2015/4/corals
Very interested in hearing your results!

So that's what a professional study by a real scientist looks like

Reading that just makes it all the more likely I produce results where the LEDs have some arbitrary spectral settings that look good to me but are not really in the same spectral ballpark as a radium. Hopefully Echotech can help me with this.

 

[A. grandis]

So that's what a professional study by a real scientist looks like

Reading that just makes it all the more likely I produce results where the LEDs have some arbitrary spectral settings that look good to me but are not really in the same spectral ballpark as a radium. Hopefully Echotech can help me with this.

Well, they should be able to. They published a really clean and nice PDF about the same subject.
Many people take that PDF as scientific. At least they dress up like scientists...
Besides... they made the fixture. They have to help you, so people can believe in the results.
Your avatar is yummy! I'm hungry!
Good luck!
Grandis.

 

[Centerline]

Well, they should be able to. They published a really clean and nice PDF about the same subject.
Many people take that PDF as scientific. At least they dress up like scientists...
Besides... they made the fixture. They have to help you, so people can believe in the results.
Your avatar is yummy! I'm hungry!
Good luck!
Grandis.

Lets hope so.

BTW, I ordered two dozen whale softshells from Maryland on Friday Absolutely my favorite thing in the world.
http://www.lintonseafood.com/maryland_soft_shell_crabs_s/2.htm

 

[A. grandis]

Lets hope so.

BTW, I ordered two dozen whale softshells from Maryland on Friday Absolutely my favorite thing in the world.
http://www.lintonseafood.com/maryland_soft_shell_crabs_s/2.htm

LOL!
I used to eat all kinds of good tasty food and had to stop because of my cholesterol.
I enjoy seeing pictures and I'm happy when others can eat them!!!
Eat some of that for me, ok?
Aloha,
Grandis.