LED algea scrubber DIY

Sep 23, 2008
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South-Korea
Hi all,

I will in this thread be describing an algae scrubber as described at:
http://www.aquariacentral.com/forums/showthread.php?t=161957&highlight=scrubber
Thats a greate link lots of info please read it..

I have a little 10G tank setup, it is my first salt tank ever, so i am using it as a learning tank, to perhaps later I will setup a much bigger tank.
Anyway, I wanted to do things a little different. And i love to DIY, so this is not about saving costs or so, this is just to enrich the mind..

The tank has just 2 pieces of live rock. In it are 2 inhabitands, a clown fish and a neon damsel. It also has a small annemone
i don't know the name of it, anybody knows it please let me know.

Before i build the scrubber the tank was well setup and was using a hang on the back filter.
Lighting is 2x14W white and 1 x14W blue.

I wanted to build a scrubber but a few things where of some concern to me. One was a possible leak so lots of water would spill on the floor. e.g. if a pump would fail or just a leak in a hose.
I did not want to hang a bucket over my tank as it looks a bit silly in my view.
I was worried about the light setup. The lights in above thread should be placed very close to the screen. But that means very close to water, salt water. Where I live the Voltage is 220V,so in my mind putting 220V close to saltwater no mater how well you isolate it, thats a dangerous mix.

So i came up with the idea of reserving a small part of the tank and corner that of and make it water tight and hang a screen in there. Then on the outside of the tank i would put the light. So while i was busy thinking this over i decided to make this light source a LED light source to see if it was possible to grow algae using led lights.

Below is the tank and on the left side you can see the cornered of part of the tank that houses the scrubber.
DSC_3824.jpg


So one thing that i could have done better here is that i should have got my self real black plastic. I got this plastic for free, but does not 100% block the light, thats why you also see inside the tank a sheet of blue plastic, to give the fish some night rest, while the scrubber is active in the night.

I have been running this scrubber since mid September, i made pictures of various stages, and i will put all info in this thread.

Some parts of this DIY are very simple like cutting some plastic and silicone it in the tank. Some other parts are more advanced and need an understanding in programming and Micro processors.

HUE ?? what? micro processors?
well i decided to also make my timing using a AVR micro processor just for the kick of it.
Over time i will share this stuff. But i will start with the basics of the design.
 
The basics

The basics are very simple, you corner of one part of the tank, make it water tight, drill a big hole in one side just a little under the water line to let the water in. The hole i drilled is about 30mm in diameter. This hole will provide the water that will flow over the screen.
Then on the other panel drill a smaller hole this will be the output hole where the pump will push the water back in the tank.

I used the Eheim Compact 1000 pump see picture.
compact_pump.gif


Well i can tell you that this is a big over kill for this setup.. I could have used from this series a smaller pump, but it turned out that this one was about the same price as the Compact 600 (just a dollar diff).
actualy maybe the 600 might be an over kill as well..
Anyway the good thing about this pump it is is adjustable, the light gray slide you see on the left side allows you to control how much the pump will pump.

This pump i placed inside the cornered off section. So what happens is water flows in the section trought the big hole. And the pump pumps it out trought the small hole. By adjusting the speed of the pump you adjust the setup so that you have just enough water in the section so the pump is under water.

Next thing to do is make the part where you hang the screen.
well don't know how to descibe it best, so here is a picture of what i made.
DSC_3821.jpg


Picture is made from the top. So you are looking down in the tank.
The top part is the scruber area. The bottom part of the picture shows the tank swimming area.
On the top left you can see a green pipe comming in and water is flowing out into some sort of catch tray..
This distributes the water evenly. Then you can also see the black screen under it.
The plastic plate on which the water falls from the pipe on the bottom can be slide out, so i can easly remove the screen.
Also it allows me to control the width of the cap which allows me to control the water flow over the screen. If the gap is to small or would get blocked the water would just over flow and fall down and the pump will pump it out.

So as you can see there is no way that this setup could lead to a water spill on my floor. If I have a power failure, the screen section
would just fill up to the same level as the swimming area of the tank and thats it.
When the power gets back then the action continues, water flows over the screen etc etc.

Next I will be describing the LEDS I used, and the power source to power these hungry stars...
 
LEDS used

for lighting i used power LEDS of 4W. And i used in the first try 6 White Leds and 2 blue leds in the center. I placed them like this:

W....W
....B
W....W
....B
W....W

Distance between the leds (center to center) is about 5 cm

Here is a picture of a White LED:
0030030050000112822.gif


The Led is already placed on special PCB that conducts the heat away from the LED. This is the black part with the solder points on it.
If you flip the LED over then the back side is a aluminium plate.
This plate is then mounted against your heat sink.
These leds generate a lot of heat, so you need to get rid of that heat. If you don't then you are going to lose your led. I payed about $5 per LED.
So i did not do any tests of how long they can last without a heat sink...

If you want more info on this specific LED here is the datasheet:
http://eleparts.co.kr/front/download.php?file_name=W42182.pdf
I used the PURE WHITE (W42182)

When i run these LEDS on 3.5 volt then they generate heat, and need about 700mA. But these leds can run at 4V max, but i did not try that, cause that is real max rating.
I run them on 3.8V at this level they need about 1A and the are realy bright then and generate a lot of heat. So cooling is realy needed. I Use
quite big heat sinks. But no active cooling (so no fan) and i can not keep hold of the heat sink, i would burn my hand.

So to let you know how much licht this produces, i made a setup, where i used my camera and make 2 photos of the tank using the exact
same camera settings, that is : fixed Shutter=1/80 Aperture=F4.5

the first picture shows the tank with T5 on, that is 2x14W white plus 1 14W blue.
The second picture is 8 LEDS on above the subject.

DSC_3826.jpg

(PICTURE 1)


DSC_3827.jpg


(Picture 2)

As you can see the T5 light does not penetrate deep in the water, and the live rock is not so brightly lid as in the second picture.
The picture with the LEDS as light source shows a lot more detail of the rock.
You can also see shadows on the sand when using LED's multiple shadows, cause multiple leds.

Finaly to give you an idea how much ligth only 8 of these LEDS produce here is a picture that i made with the camera in auto mode,
made during the DAY.

DSC_3834.jpg


These LEDS are realy bright you should not look at them directly as it will leave spots on your sight/vison...

So these LEDS could be used as a tank light but that is not why i got them, i got them to provide the light for the scrubber.
Maybe later i will make a full light hood for this tank with only LEDS. (other project).

Next i will explain where i get the power from to power these LEDs.
 
Man those pictures are HUGE!!!! couldn't stand to read this and couldn't make any sense of the pictures because i would need a 72 inch big screen to see it all.
 
Hi James123,

Thx for the feedback, I rescaled the pictures. Hope it looks better now, maybe also loads faster?
Any other tips for how to go about this are welcome.
 
update?

I really like this idea and want to know how the tank is doing and or any changes that you have made.

Thanks
 
Hi Ditka,

I did not update for so long as it seems that nobody is interrested in this thread.
Since my last update here i have done some changes. When i have some time i will make new pictures etc etc.
The tank is doing fine.
 
I didn't even know the thread existed. I've been using compact fluorescents for my scrubber, since they are cheap and proven. In any case, how's the scrubber doing with the LEDs? Do you still have the same color combination? Have you attempted the red/orange LEDs in conjunction with the blue ones? If so, any differences in growth?
 
I know I am quite interested in this... I am in the process of building a scrubber and am trying to pick out a lighting system. I would love to see how this is working out for you.

Amphipron, are you using the little spiral CFL's or a PC aquarium light?
 
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