The truth about lighting

[Boomer]

MIke

Hmmm man I hope she dont see this post or your delivery will be the least of my problems rofl



Oh yes for sure.

You gave me her work number once, let me go look for it ........................

[Scooterman]

Ahh, now I know where my Tanning bed lights come from!

[ScottT1980]

No, I did not make any money, I just wanted this stuff avalible to the hobbist.

Boomer, I am glad you are on our side!

I still haven't had a chance to really LEARN what I need to as far as this discussion is concerned. I know you spit out a number of sources earlier Boomer but can you give me the best source which gives P-max values for corals and the various PARs needed to reach this P-max (I don't know if there is one source for this)? I might have to buy it or at least find it in our library...

Very basic but what I am getting at is, if I know the PAR for my lighting, I know the p-max, and I know what PAR it takes to reach this P-max for a given coral, then I should be able to get growth rates at the opitimal level (a number of other factors of course but pretty solid as far as lighting is concerned).

Any speculation as to why VHO studies have not been done, well, at least not to the extent of Halides? Simply because there is a shift in the hobby towards MH or because SPS are the most light needy and MH are the most intense lights we use? Perhaps just an expense thing (isn't it always)?

Thanks again everyone for the ongoing discussion, sorry I have drifted off. It is tough when you are in the midst of thesis writing in one subject and are trying to learn other things for fun in an entirely different realm.


Take er easy
Scott T.

[mojoreef]

Scott I managed to round up some info for you. here are the spectrum/intenciy of some of the new t5 lighting
T-5 actenic blue bulb aquastik

t-5 Aquablue bulb aquastik

the T-5 straight blue bulb

and the T-5 Sun bulb


hope it helps

MIke

[mojoreef]

Oh and something on intencity, according to testing on the T5 lights
-two 39 watt t5 bulbs with no reflector puts out about 8.3 lux
-two 39 watt t5 bulbs with a standard reflector os around 18 lux
-and with the best reflector both bulbs put out about 36.6 lux
these are 4 foot bulbs. now my math is crappy so Boomer step in and correct me if I am out to lunch, but a 250 watt iwasaki would be the equavilant to ......oh man BOOMER!!!!!!!!!!!!!!!!! LOL


Mike

[Scooterman]

http://www.geocities.com/Heartland/H...7/spectra.html

[Scooterman]

Just a little interesting relational information.

http://www.thekrib.com/Plants/Tech/par-moles.html

Plants have evolved over many eons through natural selection (except maybe in Kansas) to use the energy available to them in Sunlight as efficiently as possible. This part of the spectrum which plants use is defined as Photosynthetically Active Radiation (PAR).

Human eyes have developed to utilize different wavelengths for vision as seen in the (rough) graph which shows the relationship between the daylight spectrum that reaches the Earth and the wavelengths used by plants and humans. As you can see, plants only use certain wavelengths of the electromagnetic spectrum, peaking in the blue and red regions, while the human eye can best see light in the yellow area, with the "Lumen" being used to relate the amount of light put out by bulbs that the human eye can see.

[ScottT1980]

Thanks for all the info and links Mike and Scott!

[Boomer]

Mike

Ouch, that hurts , as Boomer picks himself off the floor, after falling out of his chair. And that is hard from a recliner

about 36.6 lux

My pocket flashlight with dead batteries puts out more light than that. Ok, I'll let you slide today........I think........You mean 36,600 LUX or did you just forget the "K" 36.6 K LUX.
An Iwaskia 250 W MH ( you know it is really kinda a MV and not a true MH),puts out 18,200 LUMENS, so to convert to LUX;

LUMENS x 10.76 = LUX

18,200 x 10,76 = 195,832 LUX

OK, don't get lost here. This is at the bulb. Any radiation source follows the Inverse Square Law ( in air not water). Which means that the radiation decreases by the square of its distance form the radiation, source to the object that is to be radiated upon. So, at 2 meters from the bulb and the square of 2 being 4 or lets just say to be simple 2 x 2 = 4 and we need its reciprocal, which that is any number dived by 1. So, it = 1/4 or 25 % of light it had at the bulb. Thus, 195,832 LUX x .25 = 48,958 LUX 2 meters from the bulb or 1/2 of 19,832, 1 meter from the bulb = 97, 916 LUX. The sun on a clear day is 100,000 LUX at the ocean surface.

So the answer is almost ;

37,000 LUX vs. 200,000 LUX. Iwasaki puts out almost 5.5 times more light.

That T-5 actenic blue bulb aquastik, SED curve is an odd ball one for an Actinic light. Maybe they are just trying to get what some of us call "Actinic" which is not a true ACTINIC. They only have one peak at 420 nm


Scooterman

I see you found Mohan's stuff, so now I don't have to dig it out from my lighting file. It appeared in FAMA magazine a few years ago That first link was also nice, I don't have that one

For everyone reading this. The Krib is a great place, even though it is old.There is allot of data and info there. It is one of my secrete websites, now Scoot has blown the whistle on me Expect your own UPS package tomorrow.

with the "Lumen" being used to relate the amount of light put out by bulbs that the human eye can see.

I believe I said that a few posts back, same for LUX, foot candle, or candela .Even PAR is not the greatest but it is the best we have other than the SED curve.

I might add there is an old book that has some good info;

Light in the Aquarium, by Rolf Kubler

[tankgirl]

The purpose of the lights was to suppliment lights that were low in the blue spectrum. Back then, ,"olden days" we only had MH with about 5000K.

Boomy, Thanks so much! They still augment PAR!

Also, wouldn't the inverse-square law be in meters, not feet? And, why doesn't it work for decimals, darn it? 0.22 meters = around 8 inches, right?
(0.22 meters)^2=0.0484, and 1/0.0484= 20.66
Doesn't work?

[Scooterman]

I'm forwadring all my mail to Mike!

[Scooterman]

Tg I think that will work for any nurmeric form, you will have to convert either all to the metric system or all US standard.

[tankgirl]

Thanks, Scott, are lumens and lux metric or US?

[ScottT1980]

I don't think they are either TG...

[Scooterman]

In grenral I think light is measured in the metric terms but easily can be converted. Now as for as LUX & Lumens, these are units of light measurments. 1 LUX = .09290304 foot-candles; 1 Lumen /m2 = 0.092903 Footcandle; 1 Phot = .0000929 Footcaldles; 1 Nox = 929.0304014 Footcandle: 1 Meter Candle = 0.092903 Footcandle: thanks to conversion charts!
http://www.onlineconversion.com/