actinics and the purpose???

[Deanos]

What I don't understood is that in the ocean corals grow relatively deep in the water compared to our aquariums. But the deeper you go the less of the redish/yellow spectrum of light penetrates. So why is it that 6500K or 10000K bulbs produce the best growth in corals?

First, not all coral grow deep in the water. Many are even exposed to air during low tides.

Reef Zones

The article gives some details relating depth to amount of sunlight received and the types of corals found.

Second, the sun is infinitely brighter than the lights found atop our aquariums. I wouldn't be surprised if the deep water corals are receiving more PAR than the acros grown in an average reef tank.

 

[JHOV2324]

very informative.......

 

[Spracklcat]

From a practical farming perspective...

If you put corals under good daylight bulbs (even as low as 6500K) you will get increased growth at the expense of what we consider attractive colors--essentially you'll have bigger, browner corals. To expand on what Shaun said, the colorful pigments (some at least) that we see in corals grown under heavy actinic light are made by the coral to protect it from UV light. When the actinics are removed, the coral is not being bombarded with those wavelengths, and then doesn't have to defend itself--instead, it dedicates its energy to growth and reproduction. That is why coral farmers will grow corals primarily under daylight or natural sunlight to get fast growth, and then right before shipping the coral (2 weeks or so ) they put them under heavy actinic light to induce the production of the pigmented proteins to make the specimen attractively colored.

 

[WaterPlant]

From a practical farming perspective...

If you put corals under good daylight bulbs (even as low as 6500K) you will get increased growth at the expense of what we consider attractive colors--essentially you'll have bigger, browner corals. To expand on what Shaun said, the colorful pigments (some at least) that we see in corals grown under heavy actinic light are made by the coral to protect it from UV light. When the actinics are removed, the coral is not being bombarded with those wavelengths, and then doesn't have to defend itself--instead, it dedicates its energy to growth and reproduction. That is why coral farmers will grow corals primarily under daylight or natural sunlight to get fast growth, and then right before shipping the coral (2 weeks or so ) they put them under heavy actinic light to induce the production of the pigmented proteins to make the specimen attractively colored.

that's what I was told by a vendor too

i wonder would too much actincs cause cancer to coral? :tongue1:

 

[deelucky]

ok now that that as been cleared up i just got 2x250 retros 10k bulbs.all this is for my 90 which will be up soon.what i want to know is how much actinics for a 90.im thinking t-5 or vho.any suggestions