A Complete Idiot's Guide to Make LED Light Unit for Planted Aquarium




Please have a look at my website for more tutorials and fishy pictures: www.playsofrays.com

As always I am writing this for people who have no prior experience with LEDs, electrical and electronics works just like I never had before I did this. I will be posting a lot of pictures here and going into a lot of detail about making connections, wiring etc. So the people who know how these things are done may find it boring and unnecessary, but please bear with me.. it’s for the newbies.

In order to understand LEDs and what kind best serves your needs go to my previous post – An Idiot's guide to understand LEDs
It contains all the theoretical aspects of LEDs and in very simple language. Once you have a good understanding of what you need, read this post.

Before starting this thread I would like to thank Milad, who helped me a lot throughout this tedious process. He is an awesome guy.
I ordered the following things for Lighting from LEDGroupBuy.com:

12V 5A Power supply w/4PIN molex connector

4 pin Molex to 3 pin fan

80mm Fan Silencer

Arctic Alumina Thermal Adhesive 5g

Arctic Silver Céramique 2 - 25g

CREE LED Optics / Lens
(LED Type: CREE XT-E / XP-G / XP-E, Optic Angle: 60, Quantity in Package: 6 Pack)

CREE LED Optics / Lens
(LED Type: CREE XM-L, Optic Angle: 60, Quantity in Package: 6 Pack)

(Color: Cool White (~6500K), Group: T5, Quantity in Package: Single LED)
XML-CW-T5-3 Nos

(Quantity in Package: Single LED)

CREE XT-E Royal Blue
(Quantity in Package: Single LED)

(Color: Neutral White (4500K), Quantity in Package: 6 Pack (5% discount))
XTE-NW-6PK- 1 (6 Nos LEDs)

(Color: Warm White (3250K), Quantity in Package: Single LED)
XTE-Warm White- 3 Nos

DIM4 - 4 Port LED Sunrise/Sunset Controller V1.0
DIM4-R1.0- 1 Nos

Fan 80mm- 1 Nos

Hanging Kit for MakersLED Heatsink- 1 Nos

Inventronics 40w driver - 700mA

MakersLED Designer Heatsink Kit - Professional Grade (Length: 12 inch)

Ocean Coral White (Optic Angle: 90°)- 2 Nos

OEM Digital Multimeter DT-830B- 1 Nos

Solder Tube 10g - 2 Nos

Soldering Iron 60w- 1 Nos

Solid Wire 24awg (300 volt) - 25 feet - Black- 1 Nos.

Stranded Wire 24awg (300 volt) - 25 feet - Black

Then I got some more stuff from Home Depot –

assorted grommets
zip ties
water proof cable connectors
two pin plugs
some timers
extra wire (in case needed)

Before starting,
make sure to make a rough sketch of how you would assemble your LEDs on the Heat sink. It is very helpful to refer to it when making the circuit. Without it there will definitely be a lot of confusion and chaos. A blueprint of this is available on LEDgroupBuy.com- Blueprint
And here is mine for reference in the pictures.

Step 1: Testing the LEDs

To start, test each of the LEDs if they are working.
For testing I ordered a Multi-meter from LEDGroupBuy.com. Connect the red and black wires (with pins on the end) to the multi-meter body as shown in the picture. Now turn the knob to point to (diode) symbol as shown in the picture.

Gently touch Red wire pin to positive and black-wire pin to negative of the LED you are testing as shown in the picture. If there are no defects on the LED, it should light up.
In case the LED doesn’t light up, check the connections to the multi-meter again and whether its knob points to symbol.

An alternative way of testing (without the multi-meter) is to use two AA size batteries and connect the positive of the batteries to positive plate and negative of the batteries to negative plate of the LEDs.

Step 2: Preparing the Heat Sink.

You must have received a no. of nuts, bolts and washers. Join them in as shown in the picture. Now place them into the grooves of the heat sink as shown below. For every LED you will require 2 sets of nuts, bolts and washers. Arrange these bolts in the same way as you have made in your blue print. This gives you a rough idea of the positioning of your LEDs.

Step 3: Positioning the LEDs on the Heat Sink

Pick up one LED and put a tiny bit of thermal grease on its back. Gently put the LED on its respective position on the heat sink and press it. Once in place, tighten the nut-bolt pair on the grooves. This holds the LED in its position. Do this step for all LEDs. Now all your LEDs are fixed on the heat sink on their respective positions. Make sure that you have placed all the LEDs in a way that you are able to connect all of them in series (- of one LED is connected to + of the other -- - + - + - + - + - + ….- +)

Step 4: Pretin the LEDs and the Wires.

Now to wire all LEDs first pre-tin the connecting points of each of the LEDs. Pre-tinning is nothing but putting a small layer of soldering material on your connections.
• Heat your soldering iron. When it’s hot gently bring it in contact with one end of the soldering wire. The soldering wire immediately melts leaving a drop on the hot tip of the iron. Gently place this drop on the small connecting plates of the LED you are connecting. Let it cool. It takes about 3-5 seconds to cool off. Do this for all the LEDs. Do the same for all your wires.

Step 5: Soldering the Wires to LEDs

Now, take the wire and cut it into pieces of appropriate length. If you like you may use red wires for positive and black wires for negative. The wire should not be too long, it should not sag or touch other LEDs (because otherwise it will be damaged due to the heat of that LED). Scrap off insulation from both ends of all of these wires (about 2-3mm). Once you have cut all the pieces and scraped off their ends start soldering them.

• For this bring the hot tip of the soldering iron in contact with the pre-tinned connection plate of an LED very briefly. This will melt the shiny tin layer. As soon as this happens hold the wire with a pair of tweezers and gently push its end into the melted metal and let it cool. Once cool, it holds the wire firmly. As you make connections for each LED you can test them with the multi-meter or a battery as mentioned earlier. Repeat for all LEDs.

Pretin your wires too and then can solder them to the LEDs. This connection is considered as more reliable.

Step 6: Connecting the LEDs to Driver

In my case, I have also used DIM4 circuit which produces the day-night dimming effect. I have made power connections in the following manner. You may connect them in any other way you like.
• Out of 20 LEDs, 15 are connected to an LED Driver (I have used Inventronics 40W driver – 700 mA) An LED driver converts AC to DC on which all LEDs run.
The driver has 3 sets of connections – AC in (2wires - black and white), DC out (2 wires – red+ and black-) and Dimming Controls (3 wires – green -, purple+ and yellow x).
Two wires positive+ and negative – of the dimming control on the LED driver will go to a channel of DIM4.
In case of this particular driver, purple is positive, green is negative and yellow is not used anywhere. Remember it like this – purple – P- positive; green-is mean-hence negative and yellow-is a dirty fellow- therefore not used.

•3 Royal Blue LEDs are powered by Channel 1 of DIM 4 Circuit.
•One OCW (ocean coral white) is connected to Channel 2 of DIM4
•One OCW to Channel3 of DIM4.

For people who are not using DIM4 circuit can connect all the LEDs to the LED driver and they are good to go.

Step 7: Putting the Optics on the LEDs

Now place the optics you ordered. These optics are nothing but special lenses that concentrate light. I have used the ones that concentrate at a 60p angle; you may choose what every suits you. In order to stick them to your LEDs you can use a hot glue gun. I was not sure what to use so I ordered a thermal adhesive from LEDGroupBuy. If you are doing the same, you will receive two small tubes, combine a very small amount of both in equal proportions and use it to glue the optics. A word of caution – it smells terrible. This glue dries very quickly, so mix very small proportions every time. DO NOT USE SUPER GLUE. When heated, super glue produces fumes which clogs the LEDs and damages them. You can again test all LEDs here.

** Sometimes, the Optics wont fit the LEDs. In that case just file the inner side of the square slot of optics and then put them on the LED. It'll fit. If you put the optics imbalanced, the light beam will be imbalanced too. So try putting the optic perfectly stable on the LED.

Step 8: Finishing the Heat Sink With Fan, Splash Guard and Other Attachments

Now you can cover your LEDs with the splash guard. This is nothing but an acrylic sheet. Place 4 Upper T-slot plugs and Plastic-end Caps on each of the sides of the heat sink. On top of the heat sink place the fan along with its circular frame and fix it with nuts and bolts. Your LED unit is ready.

Step 9: Lets Talk Dimmers and Drivers

This is necessary to understand and helps you make the right connections. Dim4 has 4 channels (CH1, CH2, CH3, CH4) Two relays (R1,R2) and Power supply-in.

Each of the channels of the DIM4 is capable of lighting up to 3 LEDs and 0,1 or more drivers. Let’s consider two cases here –

• CASE I : Using DIM4 to control Drivers that are connected to LEDs:
Each channel of DIM4 can control dimming options of at least one driver. In this case DIM4 will command the Driver to dim, giving the sunrise and sunset effects. If DIM4 is connected to drivers, it will require only 500mA current.

• Case II : Using DIM4 to control LEDs directly (no LED driver):
Each channel of DIM4 can light up exactly 3 LEDs at a time. DIM4 will directly command all LEDs to give the sunrise-sunset effect. If all LEDs are connected directly to DIM4, it will require more current – (I've used 5A). Hence you will need to use – THIS

• My Case:
I have used –
i) Channel 1 for my LED Driver. This driver lights up 15 LEDs.
ii) Channel2 for OCW1 (Ocean Coral White), which is a set of 3 LEDs of color red, blue and green.
iii) Channel3 for OCW2 which again is a set of 3 LEDs – red, blue and green
iv) Channel4 for 3 Royal Blue LEDs.

• Relays: There are two relays R1 and R2 in the circuit. Relay R1 fires up as soon as Channel 1 goes live and Relay R2 fires when Channel3 goes live. Both relays give a power supply of 12V. Now these relays may be used to control your fans. I used R1 to start my fan which sits on top of theheat sink. As soon as my Channel1 goes live, it controls my LED driver connected to 15 LEDs; at the same time, relay R1 fires, turning on the fan over the heat sink to cool down the heat sink.

Step 10: Putting the Driver and DIM4 in a Box

If you are using DIM4 to light up your LEDs directly, it will produce a lot of heat. In order to cool it down you will need another small fan. For my device, I placed both my LED Driver and DIM4 inside a plastic container and attached a fan on top of it by making a circular hole on top lid right under the fan blades. I made holes on sides of the plastic box from where wires can go inside as well as for air circulation.

Step 11: Cover All the Connections

Now make all the remaining connections – the ones to driver, DIM 4 etc. Make sure you don’t leave any loose ends. Cover all the connections with electrical connectors/insulation tapes. Do not leave the soldering iron ON unattended.

Step 12: Installing the Hanging Kit

Install the hanging kit. And you are good to go.

Step 13: A Special Note About OCW LED (Ocean Coral White LED)

If you are one of those (well, I was) who "overthink", there are pretty fair chances that you can do this- (see the first picture)
OCW (Ocean Coral White) has already been soldered in series. You DO NOT have to connect it in the series.

THE PROPER WAY IS THIS- (The second picture)

Step 14: Disclaimer

This post is just how I did it and my . You may have other options and ideas. I wrote it because I didn’t find any similar post to help me when I did it. If you follow this and incur any losses/damages, then I am not responsible for it. I am also not responsible for your safety around electrical items.

Thank you for reading and watching It was a Superman presentation (never mind, lol).

Step 15: Replacing "so Many" Red Colored Wires

Those red wires were making it look shabby. Finally I found SGVA extension cable.
Its the wire which we use for connecting Computer monitor to CPU. It has 15 pins.

I cut the female part out-

Step 16:

So this is not a step but would let you know what this light can do and why did I actually made this light.
Although this DIY has many things that a beginner can learn and make an LED unit which can be used anywhere- Kitchen, Hallway, decorative purpose. But 'this' very light is to be used in my planted aquarium. It will grow live aquatic plants in an aquarium.

Step 17: After a Year: Still Going Strong

108,768 views. I feel proud that I wrote this instructible.

So I just wanted to show you all what I am doing with my light after a year or so. I have dismantled my planted tank and have started a Tanganyikan sandy shore biotope in it.
And guess what, fishes just love the sunrise and sunset effect. They are breeding like rabbits.

Here are 2 videos of the tank. Hope you'd enjoy them.

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    23 Discussions


    6 years ago on Introduction

    Good stuff, I recently did an instructable on making a CO2 system for my planted Fluval Spec 5. I haven't done my own LED lights before, but I just took apart an old Denon receiver that has a huge heat synch and fan... so now I know what I'm going to do with it. Great instructable, especially for aquarium geeks.

    5 replies

    Reply 6 years ago on Introduction

    PS... if you could give an approx. cost of materials for your build here it would be much appreciated... just a round number to give me an idea what to expect figuring I probably already have some of this stuff handy.


    Reply 5 years ago on Introduction

    Sumers mentioned LEDgroupbuy as the source for much of his material. You can look there for current prices. There is an alternative site called rapidLED that sells everything you would need also. The biggest problem with a DIY LED setup is that without a light meter (spectrograph?) you really have no way of telling if your light is not enough or too much for your purpose.


    Reply 6 years ago on Introduction

    Glad that you like it :)
    If you wanna make the exact unit like I made, It would be somewhere aroung $600-$700.
    But there are so many "fancy" things without which you can make a decent LED unit. The DIM4 controller, the heatsink that I used, number and variety of LEDs can be manipulated and you can get a decent manual on/off LED unit in maybe $150-$200. I liked your anubias. I'm gonna add some pics on the last page of this instructible. Please have a look :)


    Reply 6 years ago on Introduction

    Thanks, much appreciated. I think I'll probably go with a very similar build for my first one... dimmer and all. I have all the tools and stuff, just need to order the LED's and electrical components I don't already have. Great pics... I have a 60gal going right now with a nice substrate for plants and peacock eel and some fish... but just have some foreground swordgrass going right now because I don't have anything but a cheap LED lightstrip at the moment. I think I'll use your instructable to put one or two of these together and get that tank moving along with some higher light plants than what' I've been using. When I manage to get around to it I'll come post some pics. Thanks again.


    Reply 6 years ago on Introduction

    No it wasn't on a nano reef. It was for a planted tank.
    Go to the last page of the instructible and you will get to see how good is it.


    6 years ago on Introduction

    It is probably a good idea for an intro to include what this thing does. Esp for beginners. Is it grow light? That is what the pics below look like. I skimmed the content and then went to the last part for a pic of the completed product and there is just a pic of some dude wearing two sunglasses adjusting a camera. I am not going to wade through all the parts just to find out if this is something I would be interested in doing.

    1 reply

    Reply 6 years ago on Introduction

    Hi duskyhoffsky. Now please go through the step 16 in this instructible and you will get to know what this DIY is about.
    Thanks for letting me know the drawback :)

    in the top right of you're instructable there should be a little edit button. Then you can put the final pictures on the Instructable and maybe be featured. Hope that helps, I was also confused as to what it acctualy did.


    6 years ago on Introduction

    Very nice. I love it. I cant get the kit due to location but i will try to make my own light unit using your guidelines.


    Reply 6 years ago on Introduction

    Hi Shariq92. I did the setup after posting it here. So couldn't post the final pic. Here are the final pics. Sorry about crappy iPhone pics.


    1 year ago

    Great instructable! Looking to do the same with my setup but using the slim heat sink version from makerled. What size is your tank? I have a Do!Aqua 45cmx24cmx30xm tank. I'm trying to figure out if the 12" heatsink is sufficient or should I for the 18" heat sink?




    1 year ago

    Great Instructable! I found some cree star boards from anglia-live at a decent price, for anyone who is looking.


    3 years ago

    What is ratio of warm white to cool white leds ? Which ratio will give more natural and high CRI ?


    3 years ago

    Instead of using 3w led, Can we use few 10w led? You said power supply should be measured by 700ma but in one tutorial from youtube I saw we can even use one old computer psu which gives 12volt 17amp output. Let me know if it can be done.


    3 years ago

    Love this and am thinking of making one myself built into a low profile canopy. I myself do not need sunrise/set effects (due to room ambient light) or any other crazy settings.
    Personally just want on and off with med/high light capacity.

    how much do you think you could cut back costs on doing it this way?