Light

[rygh]

I had warm-white at first.
I switched to two deep red + 1 blue, and it definitely improved the growth.
But - was it enough to warrant the hassle? Hard to say.

I now need to make 4 x 30W sets for the big tank coming, so some decisions to make.
Hmm.

[Gigaah]

I'd determine how many lumens those 4x30w will get you. Probably..8000 lumens.

Go straight to ebay.
Here is the cheapest LED solution I've found.
http://cgi.ebay.com/50pcs-1W-Super-Brig ... 2559c5df14

I can't find the drivers I purchased but they were $1 each when i purchased 30 of them. they were 1wx3 with 12vdc in. So for 30$ you can power 60 LED's.

EDIt* here is pretty close. fyi they work at 12v in

http://cgi.ebay.com/20x-Power-Driver-3- ... 4cef8dd12a


Overall i think 1w LED's are more suitable to the application than 3w. They are easier to heatsink too. I have a tank lit with 1w LED. I use a 4' 1" square aluminum tube. On the end of the tube I fixed on a 40mm fan that blows air thru the tube and everything works good.

[rygh]

Well, I must admit that is really cheap. Wow.
Basically 50W of LEDs for $18. Amazing. Well, $20 shipping though.

The downsides:
* Only 80 lumens/watt. Not bad at all, but not fantastic.
* Totally unknown brand, on ebay. Caveat Emptor.
* Good, but not optimized wavelength.

A lot depends on how long they will be run.
Energy cost and longevity differences usually dominate those initial cost savings.

[Gigaah]

Yeah..they are definatly not the most efficient LED out there. I have some and are using them. They work. Id unno what more to say. They are the cheapest per lumen. If kept cool enough they should last quite awhile. I guess if you lose one they are pretty cheap

I know they could be lower K. If you dig around ebay you might be able to find a better color but I've searched high and low and thats probably the lowest cost you'll get in the warm LED range. The same guy sells a batch of 100 Regular cool white for like 55$ shipped. I'll bet if you message the guy he'll put together a batch of the warms for about that price.

They are not star mounted but I didn't have a problem with that. If you need star mounted your looking at a good 1.50 each if i recall right.

To be honest. Do i think they will last as long as a high quality cree..probably not. Are they ass efficient. No. Do I think given all these they are more cost effective over flourecent given potential longevity? Yes.

[rygh]

You make some good points.
I can replace them several times for the cost of a Cree.
And sure would save some money if they do work well.

What I might do is mix lots of those, with a few deep reds.

How hard was it dealing without the star mounting?
Is the bottom electrically insulated?
Can you simply bend up the tabs solder wires to those, and glue the base directly to the heat sink?

Did you ever find a data sheet on them?

[Eclip]

Sorry been away havent had time to check in on my OP. some interesting points. as far as i can tell form reading all the LED posts is that there are only a few of you at different stages of testing.

The very sucessful one that i have found is inkidu with DIY LED's and he used warm whites, deep 680nm red and 3W blues. produced nice green after 3 days on a long screen and that the side with the deep reds was better.

Gigaah you said you got results with the 1W warm whites im assuming that is what you are using now to get green growth? and do you have a spectral graph for them?

the problem with assuming the 8000lumans(lumans are human eye weighted) is that its not acurate for plants and why you find blue led's dont have any lumans/watt rating they have power outputs. The algae uses light that is usually outside our optimum viewing which makes the weighting and luman factor horrible so luman ratings mean nothing.

Up till Now
So from what rygh, inkidu, and gigaah have witness'ed there is growth with just using warm whites which i exect is because of the higher distribution of red then cool whites and there is the blue in its output to allow some growth then the cool whites. inkidu found that warm white mixed with some more blue + deep red (680nm) gives good results as seen from his picture of his scrubber after 3 days. (higher amount of red helped alot not sure if its due tot he dep red or not but probable)

This seams to be really good growth

rygh has found that just blue plus red(just red or deep red or a mixture?) works. Do you have any pictures of this i can see. We know this is true as the 50W ebay 8mm LED's that waucedah_joe used which seamed to work really well giving great algae biomass. the specs for those LED pannels are as follows
# LED Bulbs Power: 50watts. (40x Blue LEDs + 72x Red LEDs)
# Red LED wavelength: 620nm-630nm
# Blue LED wavelength: 460nm-470nm
# Red LED Bulb Lumen: 15LM x 72 Red LEDs
# Blue LED Bulb Lumen: 4LM x 40 Blue LEDs

CREE LED's are royal blue 450-465nm
blue 465-485nm
red 620-630nm

From some of my own calcs the 50W pannel can be replaced with 30W of cree now that 50W pannel did a 12x12inch square with another inch around the outside with ok growth leading to a 13"x13" square or between 144 and 169sqinches of area. one sided ofc. this works out to be only 0.32W per sqinch for good growth. It must have been hitting the right wavelengths or at least getting very close to promote green algae growth.
The problem i see with the cree LED's are that the blue is a fraction on the low side and may need some blue mixed in to cover a better blue band in comparison but this mite be good or bad its hard to tell without experimenting with both. what is obvious is that it needs the red+blue. The broard distrubution of light from the warm whites may help but is the extra light needed well im not sure but i guess having small amounts of light across the whole range can only help with the other pigments and compounds eg. carrotoniods etc.

What i think needs fine tuning is the amount of red to blue and experimentation with the deep red to red and blue to royal blue combination. From some calcs of my own i have found that with cree LED's that XPE royal blue to red should be in a ratio of 3:5 to@700mA to get very similar to the 50W grow pannel at only 30W. Essentially the SM100 could be powered with 30W or slightly less of LED's if the ratio can be found! we are close but not quite there i dont think, the grow pannel is effective and we cna mimmick but im not sure if its quite the right ratios almost i think. replicating the grow pannel would cost around $100 plus heatsinks.

Does anyone know a good place to order well priced heatsinks from? im in australia but there was mention of using just square tube with a fan blowing through it?

Sorry for the long winded post but i thort i should do a little summing up since reading all the nice development thraeds about LED's. i will start to tinking and check in the coming month or so...

[Gigaah]

I do not have a spectral graph for those LED's. However I've looked at enough spectral graphs to see most knock offs pretty closely follow cree's phosphors and havn't seen any significant deviation from cree warm white to cheapo no name warm whites.

I'm not currently useing them for algae scrubber. Those LED's were used as my experiment. The LED's were intended for and are not in use as tank lights instead. Warmwhite + blue + ultraviolet FTW

[rygh]

There are some old pics here:
viewtopic.php?f=3&t=509&start=10
But I will try to take some new ones. About the same, but darker green.

I have built a heat sink with a piece of cheap aluminum angle iron. Home-depot stuff.
See details here.
viewtopic.php?f=3&t=435&start=0
It worked OK, but not fantastic.
For the second rev, I ended up using these. You can put quite a few watts on them.
http://www.allelectronics.com/make-a-st ... OID/1.html
For my next rev, I will probably scour some local stores (silicon valley - lucky me) for surplus CPU heat sinks.

Question for Gigaah:
How hard was it dealing with bare LEDs, without the star mounting?
Is the bottom electrically insulated?
Can you simply bend up the tabs solder wires to those, and glue the base directly to the heat sink?

[rygh]

As requested, some quick pics of LED based growth.
About 5 days worth. With my horizontal design, seems to need to be cleaned more often.

[SantaMonica]

Looks really good.