for the light gurus

[RkyRickstr]

Why did my apgae disapear when my royal blue drver burn and i was running whites only?.. then my driver arives and im back to gha in d display. Are we missing something with the blue light?

[Ace25]

Blue Light (453nm) = Respiration / gas exchange
Red Light = growth

http://www.annualreviews.org/doi/pdf/10.1146/annurev.pp.33.060182.000411

[RkyRickstr]

So why are we not using more blue, say 50/50 red/blue?

[Ace25]

Blue = HEV light (http://www.google.com/search?source=ig&hl=en&rlz=&q=HEV+light), High Energy Visible, Red = LEV light, Low Energy Visible.. it takes 6 reds to equal 1 blue in terms of photon output/intensity. Photons are released from a light source at the same rate no matter the color, but the bluer on the visual scale you get, the higher the stored energy in the photon.

Trying to think of a good analogy but coming up blank on a good one.. best I can describe it, red has a max level of 1, once the LED stores a 1 in energy, it releases a red photon that is a package of energy... with blue, it stores 10, so it charges up to 10 before it releases a blue photon, so 1 blue photon contains a lot more stored energy. Not really a perfect analogy nor accurate, but it gets the point across.

[RkyRickstr]

6 coors lights equals one sam adams utopia!! :)

[RkyRickstr]

How about eliminating blue from our displays untill gha is gone?

[Ace25]

Blue is very important to corals and other things. Removing the blue isn't the right answer IMO to eliminating hair algae in a tank. There are many other factors that need to be looked at, things like flow, clean up crew, feeding, water parameter readings. It is usually a combination of several factors that lead to bad algae outbreaks in a display, all of which are correctable once identified. Since you use LEDs on a display, lowering the royal blues probably wouldn't hurt, especially if you use cool whites as well, but I don't think they need to be turned off completely. I think most LED lights have gone way overboard in the use of royal blues and I think that causes its own set of issues in a tank.

[Floyd R Turbo]

My first LED DT build will be for my 120 2x2x4, half 3W and half 20W, split between each side of the tank. One half will have 78 3W LEDs, 30 RBs, then 6 each of cool blue, cool white, WW 2700K , WW 4000K, NW 5000K, green, cyan-turquoise, and 420nm violet. I'll have each set of colors on a separate PWM dimming channel so I can tweak the intensities just right and get good color rendering and spectrum coverage. The other half will have 2 each of 20W multichips of 10000K, 14000K, 16000K, hybrid 20500K/453nm, 420nm, 430nm, 445nm, and 453nm, with each pair of chips on separate PWM dimming as well.

After over a year of sporadic reading and looking at people's tanks with 2:1 RB:CW I have agreed with many on the "aesthetics" thread on RC that the standard RB:CW build is missing a lot of something. Since I haven't seen much in the way of LED builds in person aside from these RB:CW ones, I guess I just have to do my own experimenting.

But I think that from talking to some people in the hydro industry who are starting to develop for the reef hobby, RBs by far and above all others produce the highest level of coral growth. So they are certainly the basis, but I think you're right Ace they are overdone when you include them at 65% of the total composition of the fixture.