Reefbreeders Fuge LED

Well that was insulting.

 

Sorry, I guess it came across kind of harsher than I meant it.

 

we will let ya slide this time buddy... but next time

;D

 

lol ^^^

but yea its cool dude.

 

Thanks everyone! I’m glad my explanation was helpful. One reason I love this hobby is the never ending learning curve.

Gcarrol:

You are right, I stop short of recommending heavy red spectrums over broad spectrums for growing algae for filtration purposes in marine aquaria. Right now, I see the different spectrums as equally viable as they are both proven to grow algae. However, there are many goals/factors at play in the reef aquarium and still a lot of questions. For example, while red light may be more efficient at growing algae, is the increase in efficiency large enough for a hobbyist to even benefit from or notice? How does red light effect the life cycle of the various species of algae we use for filtration in reef tanks? I don’t know the answer to these questions, however I do think, at the very least there is plenty of science to justify using these heavy red spectrum lights to do the job, and I look forward to hearing about other hobbyists long term experience with them.

I could write an essay on some of your questions...

Why use blue at all?

First, simply put, most plants grow better under a mixture of red/blue, rather than a monochromatic spectrum. This is based on practical research that does not attempt to determine the underlying mechanisms causing this observation. The exact optimal level of blue supplementation varies among species, sometimes dramatically. Since the best spectrum for most species of algae is simply not known, I do think it is better to grow under mixed light than monochromatic light, and this is a perfectly valid argument for using broad-spectrum lighting. If you want to use red light, I think any ratio between 5:1 to 1:1 (R:B) is reasonable. Some research has found ratios that algae under high R:B ratios, like 20:1, act almost like they are under monochromatic red light.

As far as the underlying mechanism for why growth rates are higher with mixed red/blue light, I’m not completely comfortable explaining it as of now. I need to research the topic more. I don’t want to provide any inaccurate information unintentionally, so I will just provide some basics, but keep in mind there is a lot more out there on this topic.

Blue light plays some physiological functions outside of photosynthesis. It is involved in gene transcription regulation in algae. I also did a quick Google search about the other potential roles of blue light in land plants. The degree a terrestrial plants stomata’s open is regulated partially by blue light. It also plays a role in phototropism, the spatial direction of plant growth. It may also be involved in new cell development, as one study found chlorophyll synthesis failed in germinating wheat seeds grown under monochromatic red light. Blue light even tells some plants when to flower. I think is safe to assume blue light plays physiologically important roles for macroalgae too, and it may increase growth rates in ways outside of photosynthesis (it would really slow growth if chlorophyll synthesis didn’t occur!).

Also, like I said above, in marine aquariums growth is not the only goal/factor at play. First, while in phytoplankton cultures we are not concerned that light will be attenuated due to depth (literally an inch into a phytoplankton culture there is no light due to high cell densities), this may be a concern in marine aquaria because as we all know, blue light can travel further in water than red light. So in our aquaria, red light will lose a portion of its efficiency advantage. I do not know how important of a factor this is, but it will vary among different aquariums with refugiums of different depths. It would not be a factor in ATSs. Second, blue light may impact sexual reproduction of certain species of algae, which means the cell releases spores into the water column. This is not something you want to happen in an aquarium. Some species however do not seem to sexually reproduce in aquaria, such as Chaetomorpha, so again this factor will likely vary in importance. The impact of light spectrum on life cycle probably varies among species. One study on Chlorella vulgaris, a phytoplankton, found a pure red spectrum induced spore release.

My thoughts on using orange light.

Orange is around 590 nm and doesn’t appear to be absorbed much by the chlorophylls. Orange photons may however be absorbed by accessory pigments and their energy transferred to chlorophylls. Still, and this is just my opinion, I don’t see the point of using orange light. Accessory pigments are important under light limiting conditions, when the plant cell needs to make use of as many photons as possible. Under non-light limiting conditions (those usually present in our aquariums) these accessory pigments may not even exist in significant amounts, and in that case I have to think replacing a red or blue LED with an orange one would be a waste. I haven’t seen any literature on orange light and phytoplankton, so that is really just an opinion. I also would worry it may encourage cyanobacteria (they absorb efficiently in the 500 – 650 nm range) growth in a probably weakly circulated refugium. I could be completely wrong though! There was one study on phytoplankton that found green supplementation was beneficial, which I found surprising. The same could be true with orange light… the only thing I can say for sure is that there is far less scientific support for using orange light than red or blue light.

Giving algae less blue light to prevent photoinhibition:

Blue photons <450 nm are especially effective at causing photoinhibition since they overexcite chlorophyll molecules, which then may react with oxygen, but remember light induced photoinhibition is both a function of the number of incident photons (PAR), and the energy level of those photons (which PAR doesn't consider). You can still get photoinhibition with excessive PAR at any wavelength. If growth rates are really poor and you suspect it is due to light induced photoinhibition, I think turning down light intensity, rather than turning down blue light, would be easiest. This is a really complicated issue, and we could go on for a long time without coming to any conclusion. There may be some merit to your idea, however there are so many factors at play... different color LEDs may have different efficiencies, PAR vs. photon energy, etc.

Also, photoinhibition can also be caused by other stresses such as nutrient limitation and non-optimal salinity. So if you are not getting much growth, there are factors to look at other than light intensity/spectrum.

It should also be stated that algae, like corals, can adapt to a range of light intensities (photoprotection). For example, phytoplankton respond to high light by reducing chlorophyll, while increasing carotenoids. This acclimation works on the time scale of hours to days, and helps the algae cope with light stress but is only effective up to a certain point. After a period of time under excessive light (depending on how excessive), photoinhibition may occur. Photoinhibition can also be caused by other stresses, such as nutrient limitation.

Would it be possible to give algae lower levels of blue light and still achieve the same growth?

You can achieve the same growth with a variety of spectrums – various red and blue mixes, and broad – so yes. You may require different energy input, or not. It likely varies among species.

 

I have a pair of the reefkeepers 120w controllable leds, only for about a month and a half and they have been awesome so far...!!!!! the fuge light looks bad@ss... as soon as i build my new fuges im going to be adding one of these badboys!!!

p.s. thanks jerry and everyone else for the good info... definitely leaves me much better informed and how decisions still need to be made for the lighting. I think im going to try the reef-keepers fuge led! hopefully a good report will follow. only true advantage is the power saving of the led over fluorescent... be it that its minuscule but it all adds up with all the power going into this awesomeness!

 

Bump... So how's the growth rate? And can I get a $30 13W bulb that seems to be the same thing?
HTG Supply - LED Spotlight Bulb TriBand Spectrum - ONE
Ready to dump my CFLs

 

I have been running a reefbreeders fuge light for a couple months now and it is working well. I did not use a CFL before so I can't comment on that, but one would think more PAR should allow more growth, all things being equal. I have a PAR meter from my reefclub this weekend and will take some measurments.

 

I used CFL then tried full spectrum LED. Could not get chaeto to grow in my fuge for more than two weeks without dieing. Tried the Reefbreeders fuge LED and chaeto growth is very good. My thought is that algae in the DT will not receive light in the red spectrum as it will in the fuge. My plan was to provide a better environment in the fuge for algae to grow, and it has.

 

I ordered the Reef Breeders fuge LED and am waiting for it to ship! I'm glad to hear it's working well for you and others.