What T5 bulbs promote the most coral growth?

[EricTheRed]

Howdy, all.

I was wondering what your thoughts are in regards to T5 bulbs that promote coral growth? At present time, my tank is too blue for my liking and I don't seem to see much growth in my coral. (LPS and Softies)

I'm planning on adding another "daylight" bulb and was wondering if anyone had any suggestions? I'm looking for something to promote growth.

fyi...right now I'm running 5 bulbs:

1 - ATI Aquablue Special (full spectrum 15K w/ elevated blue peak)
1 - ATI Purple Plus (it's like a KZ Fiji Purple)
1 - UVL Super Actinic (it's a 420nm)
2 - ATI Blue Plus (mostly 460nm)

I'm looking at a GE 6500....your thougths and ideas are welcome!

 

[GlassMunky]

Not an expert on this, but from my general understanding, 10K bulbs generally give faster growth rates while the higher K bulbs like 15 and 20 give you slower growth but more color. I'd say get some 10K Day bulbs and that should help some. HTH

 

[EricTheRed]

Thanks. I wasn't sure if the temperature ratings had anything to do with it or if it was the wavelength of the bulb.

 

[TylerHaworth]

im currently running:

ATI Blue Plus
UVL Actinic White
ATI Blue Plus
ATI Aquablue Special
ATI Blue Plus

I have seen an astounding growth rate increase since I changed to this combination from my old configuration (which I cant remember, but they were all UVL bulbs)...

 

[chipmunkofdoom2]

Thanks. I wasn't sure if the temperature ratings had anything to do with it or if it was the wavelength of the bulb.

It actually has to do somewhat with the wavelength, but also with the color temp as well.

Check out this graph provided by Pet Education.com. As you can see, a 20,000K bulb contains all different wavelengths, more so toward the Blue/Violet end of the spectrum. The 10,000k bulb also contains all the colors, but it has more toward the red end of the spectrum. The lower the K* rating you have, the more reds you have and the less blues. Generally, we associate lower K* bulbs with increased coral and algal growth.

The whole K* temperature rating, IMO, has gotten a little overused and very much misunderstood. Many manufacturers kind of "fudge the numbers" a bit when it comes to naming their bulbs anyway. Basically, if you were to heat a black body to 20,000 degrees Kelvin, the color the black body would emit should be around our 20,000K bulbs we use for our aquariums. Black bodies are only theoretical objects, so there's no way anyone has done the testing to be sure. We have approximates, but that's why I think it's silly to use K* ratings at all. If it's something we're only approximating, then the manufacturers are free to "approximate" some more, and by the time you put the DE bulb in your HQI fixture, the 20,000K label it carries is actually nowhere near the true "approximation" of the color. Approximations of approximations just seem folly to me.

At any rate, I'm sure many T5 users will chime in with their recommendations, because there are a wide variety of T5 bulbs that you can choose from, some without color temp or wavelenght ratings that actually produce a very good amount of PAR and would be great regardless of the color. Just bear in mind that the lower the color temperature, the more white/yellow the bulb and the higher the coral growth should be. The higher the color temp, the more blue and more colors you will see, but generally less growth.

 

[EricTheRed]

It actually has to do somewhat with the wavelength, but also with the color temp as well.

Check out this graph provided by Pet Education.com. As you can see, a 20,000K bulb contains all different wavelengths, more so toward the Blue/Violet end of the spectrum. The 10,000k bulb also contains all the colors, but it has more toward the red end of the spectrum. The lower the K* rating you have, the more reds you have and the less blues. Generally, we associate lower K* bulbs with increased coral and algal growth.

The whole K* temperature rating, IMO, has gotten a little overused and very much misunderstood. Many manufacturers kind of "fudge the numbers" a bit when it comes to naming their bulbs anyway. Basically, if you were to heat a black body to 20,000 degrees Kelvin, the color the black body would emit should be around our 20,000K bulbs we use for our aquariums. Black bodies are only theoretical objects, so there's no way anyone has done the testing to be sure. We have approximates, but that's why I think it's silly to use K* ratings at all. If it's something we're only approximating, then the manufacturers are free to "approximate" some more, and by the time you put the DE bulb in your HQI fixture, the 20,000K label it carries is actually nowhere near the true "approximation" of the color. Approximations of approximations just seem folly to me.

At any rate, I'm sure many T5 users will chime in with their recommendations, because there are a wide variety of T5 bulbs that you can choose from, some without color temp or wavelenght ratings that actually produce a very good amount of PAR and would be great regardless of the color. Just bear in mind that the lower the color temperature, the more white/yellow the bulb and the higher the coral growth should be. The higher the color temp, the more blue and more colors you will see, but generally less growth.

Awesome info, thanks! I'm going to stick with my 1st pic, the GE 6500k bulb. I will have plenty of blue from the others to mask the yellows.