Please clear up the myths

Love hate relationship with lfs.Giving me conflicting info

I have to admit my head goes fuzzy trying to understand lighting - so I want to ask 2 question (I am sure I will follow up)

#1 what does antic lighting do and is it perceived by the live stock as daylight?
#2 how long should antics be on during the day and how long 10k daylights be on?

Thanks please keep it simple

 

As for antics, my lighting never takes part in any antics.

1) The actinic bulbs are a low PAR (photosynthetically available radiation) type of lighting option. Most people use these bulbs to make the florescent in their corals and inverts to pop out more than they normally would. They are also used to offset the yellow of some of the 10000K bulbs. Livestock can use the PAR from these bulbs, but there really isn't much.

2) The length of time your lights are on is up to you. Some people run their actinics for 12 hours and all bulbs on for 8 hours. Personally, I don't like the all blue look of actinics, so all my bulbs are on for 8 hours.

That is as simple as I can make it.

 

OK... look at lighting this way.

At the surface of the ocean, sun light is unattenuated by water. It is full spectrum. Lots of yellow and red light spectrums. Those are higher frequency visible light.

As the sun light travels down through the water... yellow and reds get absorbed, attenuated by the water. The deeper you go, the only visible light left is the slower blues and purples.

10K light is surface light. 14K light is middle light on a reef. 20K light is deep water on the reef.... and yes corals live at deep water too.

So PAR has some yellows and reds, but blues to, actinics give a deeper look and make florescences pop out. It is an aesthetic thing. If you don't like the actinic look fine...

However... High noon does not happen instantly. Most folks run actinics 12 hours and day light for 8. 2 hours of actinics in the morning anf evening to simulate dusk and dawn and give a more natural scheme for the inhabitants. It's not all about you.;D

 

Actually I love the blue actinic look - I do have them on 12 hours a day (just wondering if it would hurt if they were on longer) do actinic light promote algae growth or phytoplankton? (the lfs said yes it did)

is there a difference between blue t5's and actinic t5's

 

as far as I understand the blue light may be lower in par, but is considered higher in pur. Light is not black and white :, so your really going to have to make up your own mind on this one. The way I see it is that there are quite a few ways to measure light for different reasons. Because people don't completely agree on what light is needed it can be hard to agree on a way to measure light. I try to think about light in two ways, color or wave length, and power or irradiance.
I recently asked a few questions about par and light. Maybe this thread will help a little, I started out trying to understand par and it grew to looking at light in general more. http://www.3reef.com/forums/reef-lighting/understanding-par-102951.html

 

What are they trying to sell you?

 

The light period in the ocean in the tropics where we get our coral from is right around 12 hours every day. So there is no need for the actinics to be on longer than 12 hours. It probably helps but does not promote it like other wave lengths. T5 blue light is around 460nm and T5 Actinic is around 420nm so yes there is a difference. The blue has much more PAR than actinic. Most likely more PUR also.

 

It seems to be mostly for aesthetics. As for par, they do put out some, but only about 1/2 of a 10Kish bulb. There is of course a possibility that some corals may need that wavelength, but little evidence that this is common. Personnel, I have had thriving tanks without actinics, but have never seen anyone be able to keep a tank going with just actinics (although I've seen a few people try). In my current tank, at night, once the daylight lights turn off and the only the actinics are on, all my corals close up and go to bed.
As for the photo period, I agree with others, some light for 12 hours or so, but doesn't have to be full output for all 12.

 

Thank you for the link - I did read those (about 4 different articles)

I have to read them again tho - b/c it just made me more confused

 

Nothing really - I was just wondering if out of my 4 light system if I should go with 3 10k and 1 actinic - I was asking what the draw back would be.

it's a 75gal and didn't want to over kill on light.