LED lights in fuge- do they work?

[CookieJar]

Does anyone use LEDs for their fuge for growing cheato or other macro algae? If so how do they work for you and how do they compare to compact fluorescents? I ask because I tried LEDs for growing cheato and had no luck.

My experience: I started with 2 compact flourescents lights for a 25 gallon fuge and cheato grew pretty well. After reading this article: http://reefbuilders.com/2010/08/26/inexpensive-led-grow-lights-a-great-option-for-refugiums-low-light-or-freshwater-tanks/
I decided to 'upgrade' to LEDs for growing my cheato thinking less power & more PAR (I measured outside the tank) would be an upgrade. I was wrong. After swapping out the CFLs with 2 LEDs (from: http://www.orchidweb.com/detail.aspx?ID=2428 1 chip tech, 1 60 diode LED) and checking on my fuge a week later I saw the cheato which had comsumed ~75% of the fuge had withered away to only ~30% and was soft and obviously on the decline. So I'm thinking this spectrum of LED is not good for cheato, or the 2 LEDs were too intense for the cheato, if that's possible. Has anyone had this kind of experience or can lend any insight?

 

[Coral reefer]

I'm using a 3 led spotlight type for my chaeto grows great. Got it from hd, screws into a reflector just like the cfl bulbs do. Maybe the transition freaked it out? I think my spectrum was less than 6500k, not sure tho

 

[Sfork]

I had 2 3w warm white cree's over my fuge and it worked pretty good. I had bad luck with the low power type of LED.

 

[rygh]

I have been growing algae for years with LED.
While it is all turf-scrubber now, for a while, I was growing Cheato.

It really looks like those bulbs are simply too weak.
They say they are only 4 watts, which probably also includes the power supply.
Plus, they are made of the tiny inefficient diodes.

My quick suggestion: (1 warm white + 1 royal blue + 2 red)
All modern Cree XP-E 3W LEDs, running at 700 mA.
Although for a fuge, cheap china procom are probably ok.
If you have a big fuge, double that. Or at least add another red or two.
The red is key.

 

[sfsuphysics]

Has anyone had this kind of experience or can lend any insight?

Yeah, not all LEDs are created equally. To put it bluntly those LEDs in the link are 5mm LEDs and are complete junk for making light, they suck, regardless of how many you put in a bulb.

Overall, I wouldn't swap out, the higher end LEDs are not that much better per watt than fluorescent lights, and when you add enough to get the same light as your 2 CFL bulbs you'll have spent way too much IMO

 

[rygh]

Good point, the payoff on switching for a fuge is questionable at best.
Sure, you save energy, reduce heat, change bulbs less. But it is a small light anyway,
nothing like the mains.

I think there are really only three real reasons:
1) For fun/testing.
If you plan to DIY your mains, it is good practice.
2) So you never have to change your bulbs again.
And on a fuge, it is easy to forget.
3) For safety.
Depending on setup, you might have a ton of humidity and salt creep around your fuge lights.
Going from 400+ Volts, to 12V or 24V, might be a good idea.

 

[CookieJar]

yeah, I count this as a lesson learned. I thought after reading the article it was worth a try but oh well. the interesting thing is the 2 LEDs do appear to the eye as bright as CFLs, albeing a 'cleaner, whiter' color of light. Also my PAR meter had the LEDs at higher PAR than the CFLs, but I know the PAR meter is only 1 measure, and an imperfect one at that due to differences in spectrums it can't account for.

 

[rygh]

I was reading through what you said, surprised that you failed, until I saw the "Cleaner, whiter" comment.
I assume that generally means a cool white, crisp. Which internally means a lot of blue.
Which is probably why the PAR reading was pretty good.
PAR readings like blue.
Unfortunately, what you want is purple. (Lots of red)
I am rather surprised they marketed white lights as grow light. Odd.

Enclosed are the various spectrum components needed by algae.
* Not to scale on importance *
Key is the A and F. Particularly F. Hence the red + blue.
But you do need some in the other bands as well. Hence the warm white.
That is not at all like your typical cool white spectra.


Attached files /attachments/sites/default/files/Chlorophyll-f-spectrum.jpg

 

[CookieJar]

yes, IIRC the CFLs I used are 5000K and 2700K spectrums, look noticeably yellower than the LEDs, hence the cheato growth. If I do go LED for fuge i'll get plenty of red ones.
One interesting note on these bulbs is they are sold for growing Orchids, so I'm not sure why orchids would thrive with these bulbs & cheato would perish, both are plants, but I'm not a botanist and I'm sure there's a good reason.

 

[anathema]

I think you guys just solved my issue with chaeto refusing to grow. I have a 70w 20kk mh on my fuge, way blue.

 

[rygh]

Cool.

BTW: I have an actual picture from an old ATS thread.
This is a picture of one of the scrubber tiles, a few days after being scraped clean.
On the left half, I was testing my main tank LEDs. CW + RB.
On the right half, I have the normal red+blue+WW LEDs.
The left has almost no algae growth. The right is doing well.
You can even see a bit of the light color in the reflection of the water. Blue/white on left. Pink on right.



Attached files /attachments/sites/default/files/experiment_2.jpg