Ok, this is gunna be a weird question. How many watts of Actinic lighting do you need in the aquarium? Also what do the Actinic bulbs do for the aquarium? I have been looking for an answer but have been unable to find it so far….
Actinic Bulbs Question
- Thread starter mikelush78
- Start date
The actinic blue lights help the other lights penetrate the water is the way I understand it since blue is the color you see the further down in the ocean you go. How much you need depends on the size of your aquarium and the volume of water in it.
Marinemom
Marinemom
I wouldn't say that actinic lights help the other lighting penetrate deeper into the water column, but the blue spectrum of light itself does penetrate deeper.
Actinic lighting helps bring out some of the fluorescent colors of corals. It adds that blue hue to the tank. In a FO tank, actinic lighting isn't needed, but provides that ocean-like color effect. Coralline algae loves actinic lighting.
The amount of actinic lighting you "need" is probably as debateable as most topics in this hobby. For corals, you should definitely have "some," but how much depends on tank dimensions, corals being kept, and how much of the blue / purple hue you want. For example, it's quite common on a 4 bulb PC set-up to run 2 daylight bulbs and 2 actinic bulbs. I've seen others say they like the way 2 50/50 bulbs and 2 actinic bulbs make their tank look (50/50 = 50% daylight / 50% actinic phosphurs in one bulb itself; a combination bulb). Some run MHs on their tank with no actinic bulbs. Others use actinics as supplemental lighting to soften the whiteness of MHs, and others just to help create a dusk / dawn effect. There's a lot of variations depending on personal preference.
Actinic lighting helps bring out some of the fluorescent colors of corals. It adds that blue hue to the tank. In a FO tank, actinic lighting isn't needed, but provides that ocean-like color effect. Coralline algae loves actinic lighting.
The amount of actinic lighting you "need" is probably as debateable as most topics in this hobby. For corals, you should definitely have "some," but how much depends on tank dimensions, corals being kept, and how much of the blue / purple hue you want. For example, it's quite common on a 4 bulb PC set-up to run 2 daylight bulbs and 2 actinic bulbs. I've seen others say they like the way 2 50/50 bulbs and 2 actinic bulbs make their tank look (50/50 = 50% daylight / 50% actinic phosphurs in one bulb itself; a combination bulb). Some run MHs on their tank with no actinic bulbs. Others use actinics as supplemental lighting to soften the whiteness of MHs, and others just to help create a dusk / dawn effect. There's a lot of variations depending on personal preference.
I suspect that using actinic lighting has to do with increasing the amount of light at the blue end of the spectrum, as well as outside the visible spectrum (on the blue end - UV), providing a balance of light that would be much closer to what would be found underwater in the ocean.
Adding blue light does tip the scales by increasing the colors from the blue end, giving the same net result as having the red end get absorbed in nature. The ratio of blue to red becomes more in line with what it would be underwater in the ocean. This is probably why actinic is so beneficial to certain corals. The deeper the coral is found in nature, the higher the ratio of actinic to full spectrum light would be needed to duplicate the spectrum the coral is accustomed to.
I can't understand the rationale of adding blue light for penetration, since that's what penetrates best anyway. Besides, we're talking about light coming from straight overhead into very shallow water. Anything less than 4ft is insignificant to the visible spectrum. The corals would be getting way more red-end light than they can deal with when compared to the amount of blue-end light.
Knowing the depth at which a coral lives in nature can give us insight as to how 'blue' we need to make the light for them to be happy and healthy. Here's how it works...
Light is absorbed and lost to refraction in sea water starting at the red end of the spectrum. At about 7ft, the infrared part of the spectrum is gone and red is fading fast. By the time you get to 33ft, red is pretty much gone. Yellow drops out by 75ft. I cut myself at 60ft one time - I bled green. (Greenish-brown, actually) Below 100ft, there isn't too much light, something on the order of 7-10% of what's above the surface. And when the sun is at a lower angle, it's dark down there long before it gets dark topside. Everything down there is shades of bluish gray. It gets really eerie below 150ft, and is pretty well dark (1-2% of surface light) at 200ft or so, even at noon on a sunny day. I didn't want to stay there long, it was pretty creepy knowing that there were many things living down there that could see me much better than I could see them...
<Disclaimer: Yes, I have been down below 200ft a a number of times. This was done on surface supplied/tended mixed gas. DO NOT TRY THIS unless you are specially trained and have the proper equipment. If you try to do this on SCUBA gear you will either run out of air or die of oxygen toxicity. That is, if the Nitrogen Narcosis doesn't get you first. PLEASE, don't try it.>
Adding blue light does tip the scales by increasing the colors from the blue end, giving the same net result as having the red end get absorbed in nature. The ratio of blue to red becomes more in line with what it would be underwater in the ocean. This is probably why actinic is so beneficial to certain corals. The deeper the coral is found in nature, the higher the ratio of actinic to full spectrum light would be needed to duplicate the spectrum the coral is accustomed to.
I can't understand the rationale of adding blue light for penetration, since that's what penetrates best anyway. Besides, we're talking about light coming from straight overhead into very shallow water. Anything less than 4ft is insignificant to the visible spectrum. The corals would be getting way more red-end light than they can deal with when compared to the amount of blue-end light.
Knowing the depth at which a coral lives in nature can give us insight as to how 'blue' we need to make the light for them to be happy and healthy. Here's how it works...
Light is absorbed and lost to refraction in sea water starting at the red end of the spectrum. At about 7ft, the infrared part of the spectrum is gone and red is fading fast. By the time you get to 33ft, red is pretty much gone. Yellow drops out by 75ft. I cut myself at 60ft one time - I bled green. (Greenish-brown, actually) Below 100ft, there isn't too much light, something on the order of 7-10% of what's above the surface. And when the sun is at a lower angle, it's dark down there long before it gets dark topside. Everything down there is shades of bluish gray. It gets really eerie below 150ft, and is pretty well dark (1-2% of surface light) at 200ft or so, even at noon on a sunny day. I didn't want to stay there long, it was pretty creepy knowing that there were many things living down there that could see me much better than I could see them...
<Disclaimer: Yes, I have been down below 200ft a a number of times. This was done on surface supplied/tended mixed gas. DO NOT TRY THIS unless you are specially trained and have the proper equipment. If you try to do this on SCUBA gear you will either run out of air or die of oxygen toxicity. That is, if the Nitrogen Narcosis doesn't get you first. PLEASE, don't try it.>