Actinic Led

[jeffaquarius]

You made a good choice that perfectly balance out your lighting. I might consider getting me the 48" to supplement my 48" Marineland Reef capable in my 60 gal tank.

 

[Schgred]

You made a good choice that perfectly balance out your lighting. I might consider getting me the 48" to supplement my 48" Marineland Reef capable in my 60 gal tank.

I am happy with it. It isn't perfect but overall it is much better than the reef capable led on its own.

Help me understand lighting requirements for corals. My corals have only been in the tank for 1 month but they are doing fine. Generally SPS corals require higher lighting. With the setup I have now with the additional 1 watt LEDs would I still consider my lighting system low to moderate lighting? Without having a par meter i cant tell exactly what i have but does the additional light add to the total par rating that is in the tank or would it only add to the par rating in the tank if I added a brighter light? I'm just trying to understand what lights can grow what coral.

 

[Gregcoyote]

It is cumulative. Adding light adds to PAR.


Hard to tell without meter. Different emitters have different efficiencies and add lenses, it can vary a lot between fixtures. That's why we recommend certain fixtures for certain tank sizes. But in general, a couple of watts per gallon would be minimum to me to get started with easy corals.

 

[jeffaquarius]

This depends on the depth of your tank. It is true that the lumen or PAR are cumulative but lesser wattage LED would have difficulty on penetrating the bottom of tank. This is why LED lenses with narrow angle like 90 deg are available so it can zoom in efficiently to the bottom. Actinic can also go deeper more efficiently compared to full spectrum like the 10000k.

 

[Schgred]

The tank is 22" deep. Either way I am thinking it would be helpful to read the actual par rating in the tank.

 

[jeffaquarius]

Marineland Reef Capable specs says that at 24 inch below, the PAR is 64 in the middle. Front and back would be about 15. With your additional actinic it would be approximately twice as that.

 

[Schgred]

If it is double that in the middle you are saying that at 24" below the fixture it is 128? Obviously this would be somewhat of a guess but I can't assume the par is doubled from what it was before I added the extra actinic can I?

 

[jeffaquarius]

Yes actinic contributes more PAR than full spectrum. Since Marineland has about 3340 lumen and your strip assuming has 2600 then the ratio would be about 2/3. So the total PAR would have another 2/3 PAR of Marineland.

 

[Gregcoyote]

Yes actinic contributes more PAR than full spectrum. Since Marineland has about 3340 lumen and your strip assuming has 2600 then it would be reasonable to get the ratio which is 2/3. So the total PAR would have another 2/3 PAR of Marineland.

I am confused about your statement that actinic contributes more PAR than white light (full spectrum).

http://www.reefcentral.com/forums/showthread.php?t=1918382

Actinic light is used to color up the corals.

 

[jeffaquarius]

I am confused about your statement that actinic contributes more PAR than white light (full spectrum).

Most corals prefer shorter wavelength lights which is the actinic. Given same wattage and lumen for actinic and full range (10000k) the PAR of actinic is more than the other.

 

[Gregcoyote]

Read the thread I posted. It goes into detail about this exact topic. My PAR meter shows the opposite. What does your PAR meter show with just blues then just whites Mr_X? I know you have a meter too. Understanding you probably have more blue emitters than white. I grew lots of coral with just MH before actinics became popular. PUR would be a better number for comparison, but I am unsure how to get a PUR reading from my meter.

Lumen for lumen, corals do use a lot of blue light. But they use other frequencies as well. But at white frequencies, nuisance algae has an advantage and your corals will grow fast but be browner.

Here's another thread:

http://www.nano-reef.com/topic/65551-actinic-purely-aesthetic/

It's a good topic as there is some different opinions.

 

[jeffaquarius]

Read the thread I posted. It goes into detail about this exact topic. My PAR meter shows the opposite. What does your PAR meter show with just blues then just whites Mr_X? I know you have a meter too. Understanding you probably have more blue emitters than white. I grew lots of coral with just MH before actinics became popular. PUR would be a better number for comparison, but I am unsure how to get a PUR reading from my meter.

Lumen for lumen, corals do use a lot of blue light. But they use other frequencies as well. But at white frequencies, nuisance algae has an advantage and your corals will grow fast but be browner.

Here's another thread:

Actinic purely aesthetic?? - Lighting Forum - Nano-Reef.com Forums

It's a good topic as there is some different opinions.

I notice there are some confusions on that link. When we talk about PAR (Photosynthetically Available Radiation) it is the total radiation generated by the light source with wavelength between 350 to 750 nm (actinic blue to red). If you look at the spectrograph of a lighting fixture you will notice a certain wavelength is more pronounced than the rests. The PAR is the total emission of light coming from that fixture while the PUR (Photosynthetically Usable Radiation) is the specific wavelength of that light being absorbed by a specific corals we are dealing with. Keep in mind that different types of corals prefer different wavelengths (colors) or combination of colors. What that means is that the PUR depends on which corals you have in your tank. Some corals prefers more actinic and some prefers combinations of colors from blue to red. Now lets consider a pure actinic light. Its spectrograph will emphasize the blue which is the shorter wavelength. If your corals prefer the blue then your PUR is almost equal to PAR. The PUR can only be less or equal to PAR.

 

[mr_X]

On my straight blue and white unit, The PAR coming from the blue at "X" distance was 100, while just the whites, was 72. I have been growing assorted corals just under the blues in one of my tanks for some time now. Decent growth and coloration, but less than the main tank with both on at 100%. FYI, I have montipora a little further away than "X", and don't use the whites at all in this tank. PUR must be much higher than PAR in this case, or would it be safe to assume that montipora does well under less than 100 PAR?

 

[jeffaquarius]

As I have mentioned, PAR is the total reading of the lighting fixture radiated into a particular space in the tank. It includes all the colors or wavelengths within the spectrum coming out from the fixture available for photosynthetic life including plants and corals. While PUR is the colors on that PAR where the corals utilize for photosynthesis. It only follows that PUR can never be more than PAR given same fixture.

 

[Gregcoyote]

On my straight blue and white unit, The PAR coming from the blue at "X" distance was 100, while just the whites, was 72. I have been growing assorted corals just under the blues in one of my tanks for some time now. Decent growth and coloration, but less than the main tank with both on at 100%. FYI, I have montipora a little further away than "X", and don't use the whites at all in this tank. PUR must be much higher than PAR in this case, or would it be safe to assume that montipora does well under less than 100 PAR?

Don't you have a 2:1 ratio of blues to whites?

 

[mr_X]

No. 30 and 25.

 

[Gregcoyote]

Some monti's do fine at 100 par. I would agree that pur is never greater than par. It is the depth the coral lives at that controls the color "tuning" of its algae. Deeper the bluer it is. And par is a broad measurement of all light frequencies, so different corals will see a different pur value from the same light. Royal blue led emitters are quite a bit different than a actinic fluorescent. Never had much luck growing anything under just actinics.

 

[jeffaquarius]

Corals that are found in deeper water like mushrooms love the actinic or blue, while those corals in shallow water prefers the white sunlight. This would explain why some reefers are having problems. They wonder why some of their corals are doing fine and some are not. It is the balancing of these colors. It is true that each type of coral would receive different PUR from same light because each variety select certain wavelengths or colors. It is like the food animals eat. Your pet dog prefers only a certain brand and they will not touch any other food. The food is the PAR and the brand is the PUR.

 

[mr_X]

Not true. No corals prefer white light over blue, they just prefer more or less PAR. They don't know what color the light is.

 

[Schgred]

Here is an article that I think is also helpful:

(http://saltaquarium.about.com/od/li...rtance-Of-The-Par-Pur-Of-Your-Reef-Lights.htm)

I think I am understanding all of this. From what I am hearing PAR is the total light given while every coral has a specific need/requirement of usable light (PUR). Intensity is only a part of the lighting requirements while color from the lighting is also very important. The article sums it well with the A B and C points on the spectrum.