Modern LED scrubber light

[inkidu]

I found this interesting and a reason to go with the 680 nm led and 5 watt 660 nm deep red.

b) Emerson effect ( this is from here http://www.photosynthesisinfo.com/moder ... synthesis/ )

Emerson and Lewis (1943) measured quantum yield at different wavelengths of light. Quantum yield can be defined as number of O2 molecules released per quantum of light absorbed. A sudden drop in rate of photosynthesis was noticed at 680 mµ (red region). This sudden fall in the photosynthesis yield beyond red region of spectrum is called red drop.

Emerson et al. further noticed that photosynthetic rate can be restored if simultaneously shorter wavelength is provided. This simultaneous giving of shorter and longer wavelengths gave photosynthetic rate higher than total rate from the beams separately. This photosynthetic enhancement is referred as Emerson enhancement effect or Emerson effect. The results obtained by Emerson were as under:

(for some reason I can't upload graph but more or less 1+1= more than 2)

Photosynthesis at 700 nm = 10

Photosynthesis at 653 nm = 43.5

Photosynthesis at 653 + 700 nm = 72.5


With there combined spectral power distribution curves(660 and 680 nm) and setup to have a similar light output, I am

going to shoot for around 400 mW per led, I might be able to achieve a fairly consistent output between 660 and 680 and will

have about a .65 relative spectral power for 650 nm and a .2 relative spectral power for 700 nm.

Still some concerns about if the benefit is worth the 80 watts I will be using for the 680 nm led. (edited around 400mW ) 2A * 4V * 10 leds

In comparison the 660 nm ledengin would be: 1A * 2.8V * 10 leds = 28 watts for over 500 mW a piece

As always please any input would be appreciated I am far from an expert.

I will pickup some 650 from the xp-g warm whites also. I would hit the whole red spectrum from 600 to 700nm.

It would be nice to figure how much 650 is contributed by the xp-g's. I forgot ideally I want to stimulate the chlorophyll a (670) more than than the

chlorophyll b (650) and this would be easily enough done by dimming the xpg and/or increase power to the 680. I read that there is a way to calculate the contribution of the w/white

but it is time consuming. A person from another site explained it like this:"you would use the spectral output chart that shows the intensity as a function of wavelength and write down the relative intensity for each wavelength. Last time I did it, I used every 10 nm but the more sample wavelengths you include the more accurate your result will be. You would then have to set up an equation based on the total lumen output to discover the actuall percentage of lumens each wavelength contributes. Then convert the lumens of each wavelength to watts to remove the lumen weighting (which is why I used 10 nm increments). I suggest using a spreadsheet to do all the math for you."

[Gigaah]

I've read somewhat similar information. That in conjunction with the information I posted is why I decided to experiment with warm white and 700nm. The warms hit some blue, and sweeps over to get some yellow, lots of orange and red but drops off too much before 700nm which is why I wanted to put in a 700nm deep red.

[rygh]

Wow, Inkidu really has some good growth there. Major jealousy.
But looking at the irregular pattern, and the picture of the LEDs, you might have a light dispersion issue.

I am still just growing a pale yellow algae mixture.
It grows ok, given my low nutrients, but it is not that green.
I shaded a section of the screen with duct tape, and that section did turn green fairly quickly.
However, that section did not grow nearly as much algae mass.
I am going to try more flow, and maybe less flow, as well. Just to double check that it is not an issue.
I am also playing with on/off cycle a bit more.

It is fairly green under the CFL-flood test section as well. Although some yellow. But again, less algae mass there.
I tried the duct tape light blocker there as well, and it was more green, but started to die off as well.

Since this setup is with pure red+blue, and my original test system with red+white produced green, that there might
be a real problem with the missing spectrums.
It grows, but it grows the wrong type of algae. Not entirely sure I care, but I think I do.
I think if I did have a lot of nutrients that I would care, since I really doubt it grows as fast. Too solid.

N/P are still 0.
Algae in the main tank is still weakly growing. Not dying. Better than no ATS, by a lot, but not there yet.

[rygh]

I am really confused by the amount of power.
I have a 25W system which really appears to be too bright and frying the algae.
I have been busy adding duct tape to screen out regions
Yet Inkidu has a 135W system that seems to be growing great.
We both have almost exactly the same size screen.

Inkidu, some key questions:
1) What is your flow rate?
Maybe I am way off there.
2) Is it running full power?
You have a controllable supply. Just wondering how it was set. Measured?
Especially looking at that picture. My camera cannot handle anything close to a direct shot like that.

Maybe the power has to match the nutrients? That doesn't really make sense though.

[inkidu]

I have an Azoo Powerhead Model 1800 which supplies 475 gph, I would guestimate 380 with a 8" lift hard

to tell (powerheads don't pump up so well).

As far as I know you need to turn down(current) manual on any meanwell driver for it to be any different than what the

driver is spec at. So no I have not done any adjustments or for that matter measured i.e. I just planned my drivers to fit very well with the load.

That is also to say if anything goes wrong the driver would almost certainly turn off because it's out of the normal range. (just an assumption here)

Don't let the picture fool you they are really bright the picture is just being taken at a very oblique angle.

I hear what your saying about the uneven growth something I am playing with. I got a Lee sample pack of filters

http://www.leefilters.com/

I was not sure what to use so I just used an assortment of the diffusion film that came with the sample pack(only say 1.5" by 3" inch),

and that might be some of the reason that there is some splotchy growth i.e. different levels of diffusion. It is overpowered. I contacted the one

company about the pattern diffusion glass. Something that I feel will break led use for scrubbers wide open.

http://www.guardian.com/en/na/gp_016074.html You could use high power leds, therefore eliminating the diy headache, mix the colors well and

place the leds very close to the screen without the risk of hot spots.

I have been given the cooled shoulder by the company. I did find out that it is made in Spain and not in the USA (my home town)which is part of the problem

(they don't want to bother with small orders not that I blame them) but I am working on that. Using duct tape ??? If you were using typical lighting

I would go with what SM always tells people (hope you don't mine SM and I get it right) If you think there is to much light try to increase flow if you can,

if not move the lights back but since you are using leds there could be other factors involved. I wonder if a little more time for everything to find its place

might help? Trying to work it out myself.

Hope this helps.

[rygh]

Same flow as me. Thanks.
The side with the CFL flood is not doing great either, so I am really thinking that it is a simple matter of almost no nutrients.
I did turn the skimmer off and increased feeding a bit, but not a lot yet.

One thought I had on light diffusion is to light it indirectly. Have the LEDs on the side, pointed slightly up. Paint entire box flat white.
Flat white paint reflects great. Like 80%+, and in a very random direction. Super cheap and simple as well.
I did that on a regular light in my den. Replaced a halogen torchier light with an LED light, purely bouncing off the ceiling. Worked great.

I will keep tinkering. I might add the warm whites from my previous build.

Yes, duct tape. :lol:
Worlds fastest way to make a reflective surface.

[inkidu]

Still like this product for reflection. whiteopitcs film(can handle some moisture) every time I think of it its after 5pm

http://whiteoptics.com/?page_id=12 It might be expensive???

I am taking your advice and thinking about using more blue but want to expand my blue spectrum from what the 450nm blue the xp-g gives me.

I want something that hits one of chloro directly in this case b (still having some trouble finding what I want in a 430nm leds i.e. chloro a

"gallium nitride on a silicon carbide substrate" is what I think is needed for 430nm????) Still a ? in my mind about how much blue is needed.

- XPEBLU-L1-B40-K3-0-01 Blue 470-480nm 35.2 Lumen @350mA from cutter

[rygh]

There are plenty of 5mm round LEDs in the 420nm and even UV range, but those are weak.
Looks like Nichea makes some 2W version for 380nm, but I don't see a supplier.
Although a few for sale as flashlight bulbs.

Good paint won't really have a problem with moisture, as long as you spray it on acrylic.
I used some to paint PVC pipes dark blue in my main tank.
And for that matter, the paint can be on the outside.

[SantaMonica]

Trust me, you have enough nutrients, especially since the skimmer is not removing any. If you are growing pale green, then it has nutrients. Pale green is just burned, that's all. Probably because the 25 watts are focused into hot spots that's don't appear to your eyes. Just reduce the ON time to fix it.

The white reflective ideas has merit; is similar to the edge-lit ideas tossed around last year:

[rygh]

Trust me, you have enough nutrients, especially since the skimmer is not removing any. If you are growing pale green, then it has nutrients. Pale green is just burned, that's all. Probably because the 25 watts are focused into hot spots that's don't appear to your eyes. Just reduce the ON time to fix it.:

Sounds good.
Changing to 5/7/5/7 on/off/on/off, so 4 hours less per day.
Also, I am going to add a bunch more panels of diffusion grating.
Looking at my quick duct tape fix, it does seem to be growing best just under the edge, but not too far.

Longer term, I am thinking of a rev-3:
1) Extend LED the entire length. So no more CFL test area.
2) Mount LEDs on the side, angled up a bit, using white-paint diffusion idea.
3) Add 5 warm-white 3W LEDs.