Step 1: Materials
Black plastic sheet
DC power supply
Step 2: Designing Light Layout
Step 2: Measure the lip of the tank so your piece of acrylic will fit nicely. Remember to cut it a bit smaller because you will have to add your aluminum trim later on which is about a 1/4 of an inch on each side. I'm not sure of the proper way to cut the acrylic, I just used a knife and cut where i wanted and then bent the acrylic and it will break off very nicely.I bought a piece of acrylic at the local hardware store I think it was about $4
Step 3 After you figure out the position you want your LED's and cut the acrylic to desired shape the next step is to drill into the piece of acrylic where you want to put your lights. You should drill the holes so that the led holder of your choice fits nice and snug i'm sure if it is a little bigger or smaller it is okay.
Step 3: Adding LED Holders
Step 4: Adding the LED's
I bought my lights off of ebay like everything from this project basically. Before I started this project I had no idea how LED's worked or anything about lights or electricity. To put the LED's in the holders you just take the little clear plastic end that comes with the holders and stick the two ends of the LED through the two holes in the clear plastic holder. The Positive end of the LED is the longer end of the barb. The negative is the smaller end. If you happen to cut the ends so you cant tell which is longer, you can look inside the LED and the metal piece that is smaller inside the LED is the positive side. I lined up all of the positive ends facing the same way so they went positive negative positive negative, and so on. http://led.linear1.org/led.wiz this website will give you an example of what your wiring should look like and what resistors you should use.
You will also need resistor which you can get on ebay or at any local electronic store. To determine the amount of resistance you will need for your lights you will need to use Ohm's law which is I=V/R or you can just type in LED calculator on google or whichever search engine you use. For my lights I needed to use a 100 Ohm resistor for a series of 3 lights. You will be able to type in your power source voltage, forward voltage, forward current, and the number of leds you want in your array from the link in the above step. The resistors are not polar sensitive so can go on either the positive or the negative it doesn't really matter.
On my light I wanted to have a moonlight switch so make sure whichever lights you want to be your moonlights make those blue. You are going to have to wire them separately from the white ones to be able to just have the blue lights on. You can have all of the negatives together but the blue positives should be soldered together separately.
I sanded my LED's to try and diffuse the light a bit but it still made a beam of light into the water. I then tried to put hot glue on the end of the holders and that did the trick. You may like the beams of light personally I didn't so just use some hot glue and it will fix that and waterproof it.
Step 5: Finishing Aquarium Light
Next I added the aluminum trim around the edges to make the light more sturdy and give it a nice look. I got the trim from my local hardware store for like 6 bucks total. I just drilled a hole through the aluminum and into the acrylic. I forgot to say earlier, when drilling through the acrylic you can have the drill at a fast speed just make sure you don't put a lot of pressure on the material because it cracks relatively easily. after you drill the desired amount of holes to hold the trim onto the acrylic you can add your nuts and bolts to hold it together.
You will want to wire a wire from the positive from all your white lights to your desired switch. Then to the power supply mine is a 12 V camera charger you can use just about anything as long as it is DC current. Then you will want to wire all of your blue lights from the positive end to the other switch or if you have a three way switch. The negative ends of your light series can go to the negative end to the power supply it doesn't matter if they are from your white lights or your blue lights. If your like me and wanted a clean look you can buy some female DC connectors to connect your lights to the power supply and since I have a 55 gal tank I used these to connect each half of my lights to the other.
Next I attached the black cover I cut out of a plastic sheet I got from Menards, and cut a hole for my switch to fit in nicely. And that is it your ready to turn the lights on on and hope it works haha. Please feel free to ask any questions, because i'm sure I am missing something. Feel free to also criticize or give feedback on what you think I could do differently.It is very easy once you figure out how everything works.