The truth about lighting

[Scooterman]

http://www.animalnetwork.com/fish2/a.../1/default.asp

This one has a better explanations.

[mojoreef]

Boy this one maybe a good one for me to watch,hehehe.
K is the tempature of the bulb. the temp will effect the color of the bulb to our eyes but also the wavelengths of color waves being generated. Corals zoox have the ability to absorb certain wavelengths directly (violet and Blue) and the abiltiy to absorb other wavelengths with some manipulation (use of pigments) and still the ability to deflect certain wavelegnths (uva,b) with the use of protectorant pigments.
Danna Riddle is a guy, lol, dont worry I made the same mistake just prior to meeting him. Danas line of thought is that you can measure the absorbance of light and its ability to use it by respiration and by flouresing. The concept on how corals use light is complex but give me some time and I will put a short and skinny together for you. On the color of the bulb yes it is very important to a point. low K bulbs will have no effect or use to a coral. A coral can only utilize light at certain wavelegnths, the rest are useless regardless of intencity.

Give me some time and I will put something together.

Mike

[tankgirl]

Am catching up, still haven't read the whole thread, but gotta comment on this from Calvo;

it is better to underlight your tank than underfeed your corals.

I find that hard to believe and doubt if any of us is going to try it.

[mojoreef]

yea I would have to agree TG, doesnt make alot of sence. Corals are so differing in thier needs, you cant paint this with a wide brush, you have to go individual species.


Mike

[ScottT1980]

So, at least to this point in the discussion, it is fair to say that in fact, kelvin DOES matter, perhaps not directly (although I still have some reading to do here, just way too busy), but it still can affect the PAR value. Is this a correct assumption?

This goes against what I have percieved to be the general consensus in the hobby. I always assumed a 110W bulb or a 400W MH bulb is going to have the same PAR/intensity regardless of kelvin. So true, while kelvin rating does have it aesthetic value, it also does have an intensity value that should be considered. Am I correct here? I am just drawing this conclusion from quick skimming of the actual data (without looking at much discussion, plus that RC thread is going to take me a good two hours to mull over).

TG, I agree and really was shocked to read that.

Take er easy
Scott T.

[Craig Manoukian]

Mike,

When you talk to Anthony, will you get a clarification please. Keep in mind this was a general statement to a group of 50 people. Most of what I've expeienced and heard is that we tend to underfeed our corals, though not intentionally. It makes sense to me.

[Curtswearing]

I agree we have to go individual species.

We feed corals (indirectly) with proper lighting and directly with foods. On some corals, we can underfeed 2 both ways. Or we could put a tubastrea 6 inches under 400w MH's and not feed it at all.

[mojoreef]

Yes Craig that does fall inline with the general direction people are getting pushed (feed more) One that I dont readily agree with, and still have not been able to find any solid data to back thier position.
Blanket statements about corals in general can not be made like this. Thier are alot of corals do not require any light.
Scott Kelvin does matter. if you were to place a 400K bulb over a reef and it had unbelievable intencity, it would do absolutely nothing for the corals. The quick reason that High K bulbs have less intencity is a mechcanical thing. It gets a little deep Scott, I dont really have a chance to post a good one giving the concept at this moment (babysitter 47 men on a site) but I will as soo as I get a free moment.

Mike

[ScottT1980]

NP at all Mike, we are all busy. Actually, that is why I am doing more question asking than research on my own, because right now, I am swamped. I will try to do some digging as well later on tonight if I have the chance, perhaps refreshing my memory on photosynthesis I and II as well as the wavelength requirements, etc...

I still want to see the growth studies and will continue to look for those. Of course, if these studies do exist, then most likely they will only involve one species, well, at least in the laboratory...

Anyway, thanks to everyone!

Take er easy
Scott T.

[Boomer]

Scott

Ok, lets start from the top


Have there been any studies looking at growth rates under different Kelvin bulbs to back up what everyone says, that the Kelvin rating of a bulb does not matter?

No, none that I know of.

As Mike and Witt have stated, more or less.

On the color of the bulb yes it is very important to a point. low K bulbs will have no effect or use to a coral. A coral can only utilize light at certain wavelengths, the rest are useless regardless of intensity.

Of course, lets not try to exaggerate, when we say K has no effect on growth. I believe I said as long as it is a reasonable K. Corals won't do well, at say 200K. As I pointed out in the other thread blue light puts out almost twice as much energy red light. And lets not forget what PAR means Photosynthetically Available Radiation. That is the radiation that they can use and then there is PUR, Photosynthetically Usable Radiation and there is PS, Photosynthetically Stored Radiation

Calfo made an interesting point. He believes that light supplies only up to 15% of the nutritional.

This is nonsense. Calfo seems to have missed the bazillion studies that say otherwise, often reported as P-R or CZAR. Some corals can get as high as the high 90's % of their needs just on light. And if corals and anemones did not mucate they could get over 100 % of their needs from light.

So obviously, growth studies are a bit difficult as I would assume the P-max varies from coral to coral. I wonder if there are any P-max values out there for various corals? Also, isn't P-max measured by O2 respiration .


And for you ref. I have.Many studies done, but none on bulbs. Does it make a dif , PAR is PAR be it bulb or sun.

Coral Reef Ecology, Y.I. Sorokin.......gets very deep into the subject on ( P:R) Photosynthetic Respiration Rates

Ecosystems of the World; Vol. 25 Coral Reefs, Z. Dubinsky.........as does this

Life and Death of Coral Reefs, C.Birkland

Reef Evolution.R. Wood

The Ecology of the Indonesian Seas; Parts 1 & 2, T. Tomascir

Cycles of Essential Elements, L. Pomeroy.....early uncorrected studies on P:R

A Functional Biology of Anemones, J. Shick.............here studies on anemones and this guy is the expert on the subject of P:R for anemones.

Yes they are species dependent, reef dependent, even dependant on dif parts of the coral.

so PAR rating is that, intensity of the actual light spectrum being lumens.

NO ! Lumens is a human light measurement, it does not see blue or red light very well, so it is a false or misleading measurement. PAR is measured in Einstein's

I find that hard to believe and doubt if any of us is going to try it..

Yes, TG is is bascially nonsense.

Scott see Mike's other posts, and read all those links. Have to go to work be back for a look later.

Also, have you read Eric's book and read this;


http://reefkeeping.com/issues/2003-11/eb/index.htm

[EdgeKrusher]

Just tagging along.

[ScottT1980]

Thanks for joining Boomer and thanks for the references...

I have a lot of reading to do on the subject so if I disappear for a day, don't think I have given up or forgotten.

Take er easy
Scott T.

[EdgeKrusher]

I just finished reading the interview with Dana Riddle. He states that Actinics don't actually do anything for the aquarium other than asthetics. I thought they helped the corals fluoresce.
He also mentioned that he noticed greater colors and coral growth under 6500K lights, compared to 10000K and even 20000K.

Now the question I have is how do we know the PAR of a particular brand of bulb? Not all of us can afford, or need a spectroradiometer. Do any of the companies give the PAR value of thier bulb? This is a new concept, and is not the standard, but maybe some companies are catching on.
So does any of this PAR and Kelvin stuff apply to VHO and PC lighting? I only ask this becuase all the test results, and all the experiments seem to be carried out on only MH lights.

Thanks

EK

[Scooterman]

Ahh, Einstein's, I stand corrected.
Blue light as compared to Reds, there is a frequency difference that makes them so different, Thinking out loud here but red lights are at higher frequencies thus fading much quicker, kinda like microwaves, the frequency is so high that you could point the megaton or klystron oscillator a foot away and get no ill effect! Thoughts out loud here, sorry.

[ScottT1980]

THats kind of where I am at EK. I am really starting to question my purchase of 2 actinics and 2 50/50s for my aquarium. Luckily, 220 W of "good" light are still moderatly sufficient on a 55 gallon with no SPS but I think I might have been better off with my initial setup of 1 actinic, 1 50/50, and 2 aquasuns. I would rather get good growth and have tolerable aesthetics than get reduced growth and a bit more pleasing aesthetics (but that is just my personal opinion).

Take er easy
Scott T.