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14K 175watt Metal Halide Bulb - Iwasaki
- Thread starter Daniel
- Start date
C
concept3
Guest
I think Sanjay Joshi tested that light out (he at least mentioned it during our December social)and he said it produced just as much PAR as some of the 250 watters out there (incl the 10K's). He even reccomended i drop down to the 175's on my tank which is 20 inches tall. I already had the 250 ballasts so i did not. He said it is a TRUE white with a slight tinge of blue, but most people still like to supplement actinics with it to give it that extra pop!
concept3.875 said:
Merv where did you see that about the bulbs? Do the 175w 14k Iwasaki give as much par as the 250's? I may have to try them if that's true, I was thinking of going with 250's on the 120, if these bulbs give as much par I'd rather do that than have a higher electric bill.
C
concept3
Guest
Sanjay talked to me about them in the December social.
http://www.reeflightinginfo.arvixe.com/
it seems like it is down,. don't know if he has the updated info for the Iwasaki 175 yet.
http://www.reeflightinginfo.arvixe.com/
it seems like it is down,. don't know if he has the updated info for the Iwasaki 175 yet.
C
concept3
Guest
it's up. and yes the 15K Iwasaki is in it.
C
concept3
Guest
Here is an example with an Aqualine Buschke 10K
An exerpt taken from here, also by Sanjay:
http://www.reefkeeping.com/issues/2006-03/sj/index.php
A light source is basically a continuous source of photons, in our case converting electrical energy into visible photons. So when we characterize a light source, we are interested in determining how many photons it generates per unit of time. This is called its photon flux. These photons are generated and spread in all directions, and ultimately land on some object of interest (often in our case, the corals). A light source generates photons at a constant rate, and as we move away from the source, the photons will spread over a larger area, hence fewer photons land on the target area the further we move from the light source. We are interested in how many photons land on a given area, usually 1 meter square, and this number is called the photon density. Additionally, we are interested in the photons that are available for photosynthesis, which happen to be photons in the range 400-700nm (the same as visible light). These are called photosynthetic photons. These three entities of interest combine to comprise the Photosynthetic Photon Flux Density (PPFD), which is a measure of the number of photons in the range of 400-700nm falling on a 1 meter square area per second. PPFD is a measure of Photosynthetically Available Radiation abbreviated as PAR. Recall from Part 1 that to generate 1 watt of power we would need 25.15 × 1017 photons/sec at 500nm. This is a lot of photons!!! Since we are dealing with a large number of photons, the number of photons are measured in units called micromoles (1 mole = Avogadro's number = 6.022 × 1023, hence 1 micromole = 6.022 × 1017). Hence the units of PPFD are micromoles/m2/sec, so, a PPFD of 1 corresponds to 6.022 × 1017 photons falling on a 1 meter square per second. In the aquarium hobby we often refer to light output in terms of PAR. Technically, this is incorrect. PAR is typically measured as PPFD.
An exerpt taken from here, also by Sanjay:
http://www.reefkeeping.com/issues/2006-03/sj/index.php
A light source is basically a continuous source of photons, in our case converting electrical energy into visible photons. So when we characterize a light source, we are interested in determining how many photons it generates per unit of time. This is called its photon flux. These photons are generated and spread in all directions, and ultimately land on some object of interest (often in our case, the corals). A light source generates photons at a constant rate, and as we move away from the source, the photons will spread over a larger area, hence fewer photons land on the target area the further we move from the light source. We are interested in how many photons land on a given area, usually 1 meter square, and this number is called the photon density. Additionally, we are interested in the photons that are available for photosynthesis, which happen to be photons in the range 400-700nm (the same as visible light). These are called photosynthetic photons. These three entities of interest combine to comprise the Photosynthetic Photon Flux Density (PPFD), which is a measure of the number of photons in the range of 400-700nm falling on a 1 meter square area per second. PPFD is a measure of Photosynthetically Available Radiation abbreviated as PAR. Recall from Part 1 that to generate 1 watt of power we would need 25.15 × 1017 photons/sec at 500nm. This is a lot of photons!!! Since we are dealing with a large number of photons, the number of photons are measured in units called micromoles (1 mole = Avogadro's number = 6.022 × 1023, hence 1 micromole = 6.022 × 1017). Hence the units of PPFD are micromoles/m2/sec, so, a PPFD of 1 corresponds to 6.022 × 1017 photons falling on a 1 meter square per second. In the aquarium hobby we often refer to light output in terms of PAR. Technically, this is incorrect. PAR is typically measured as PPFD.
