Many of us these days are using DIY led panels for different uses of aquariums, be it marine, planted or general use.
So I am illustrating how easy it is to make and where to find the Raw materials...

The below information is completely based on what I know, which may/May not be standard according to best practices but works for me

Raw Materials Required-
1) Alumunium Panels 110 and above Store- Hardware shops at Chandni Market
2) LED (any wattage and Voltage) For illustration, 1watt ~3v leds are used. Retail Price for 1 watt ones- White Led and warm white Rs 5/pis and any other colors (Red, Green, Blue) for Rs 10/pis. For bulk of hundred numbers, prices can go down to Rs 3 and Rs 4/pis respectively. Store- LED World
3) Starbase aka heatsink - Rs 2/pis...no bulk buy advantage Store- LED World
4) Wires - 90/coil
5) Soldering Iron and soldering Wire Iron available from 50-60 onwards, and solderring wire coil is 50/coil | Store- electrical shop at Chandni
6) Thermal Paste- Rs 20/little container | Store- electrical shop at Chandni
7) Araldite different prices fr diff quantities...dont remember the exact price but the smallest one may cost around 40-50
8) Fevi-kwik not telling

9) DC 12V Male - Female Connectors Rs 20/male-female pair | Store- electrical shop at Chandni
10) Adapter 12V DC 1amp starts from Rs 50 and goes up to thousands depending on the product. I used Rs 50 ones. Store- LED World
Aluminium Panels can be found of differnt shapes and thickness and has to be purchased atleast 12'. Price starts from 110-120 for a 12' panel of 1" thickness.
The one I used in this project is as below-
At shop, they will ask you for what length would u like to get the panels cut. for 3' I got them cut as 3' *4 (=12') and for 2' tanks 4' *3 (=12') or you can get thm cut at your desired length from the shop.
Moving onto the steps to make the whole setup-
Step 1- I had 4' panels, so I cut them according to my requirement. Them use a marker or anything to roughly finalize the points where you would like to put the leds. Note: led connections will be three leds in series when using 12V power supply.
Step 2-
Place the Starbase at the locations and chk if the distanced btwn the leds r looking fine to you.
Step 3- Fixing the starbase to the Aluminium Panel
Flip the starbases
Put Thermal paste in the middle of the starbase like as shown...Thermal paste is a highly heat conductive material which improves the contact area btwn the starbase and the alu panel for efficient heat transfer...
Put Araldite mix and fevi-kwik on the alternating arms...Here fevi kwik is used for quick fixing and araldite for long term bonding
Flip the Starbase again and hold it down by putting in some pressure for the thermal paste to spread out evenly. Within 10seconds the fevikwik will secure the bond and keep the starbase stick to the panel. Araldite will take some time to get cured
Do the same for all the star bases. Try to keep the +ve marks or -ve marks to any one side like shown in the below picture (+ve on the right and -ve on the left)-
Similarly complete fixing all the starbases like in d below picture-
Step 4- Making the Series Connection:
Connect the -ve terminal to the +ve terminal of the next starbase in the same series. Please keep in mind that for 12V we will keep only 3led in a series. Hence,from the -ve of 1st starbase to the +ve of 2nd start base will be connected and -ve of 2st starbase to the +ve of 3nd start base will be connected. Example below-
Full Picture-
Step 5-
We need to put the Series-es(sets) in parallel. that is a SET(series) OF THREE LEDs will be in parallel to Another set of THREE LEDs.
Fig Below-
Same connection in different way of representation-
Step 6- Circuit Design-
Notes-
1) No of LEDs per set/series depends on the LEDs' forward Voltage and the Adapter Output Voltage
2) The total no of LEDs that can be run using the given adapter is calculated using Adapter Output Voltage and Adapter Ampere rating.
For Example-
1)
Mathematically -
We here have 12V adapter and leds are suppose 2.5V to 3.5V. So If we want to make a series with 2.5V, then we can put (12V/2.5V) = 4.8 Leds or 5 Leds.
Practically, If you put three Leds of 2.5V = they will be kind of overclocked u can say coz then they will be operating on 4V which is 1.5V extra. This works and I have checked that. Only thing is the leds gets quite v hot which lessens its life span while providing great luminosity. We can also mix and match the Leds of different Voltage in the set/series and it will work as long as the Required Voltage to run the Leds dont fall too short.
2)
After Voltage, Ampere rating of the Adapter used, has to be kept in mind. A circuit must not have more power requirement than the Adapter can supply.
For Example -
Power supply Capacity of the Adapter = 12V x 1amp = 12watts, This means, we can run 12x1watt LEDs for a Adapter with 12V 1amp o/p.
In case the power requirement is more than the adapter can supply, the adapter may burn out.
Step 7- Making the sets parallel-
What it is generally done is- makeing holes on the panel to do the wiring in the back ground. so make holes at required areas for the wires to pass through to the opposite side like this-
All the connections are functionally done as per the Circuit diagram above-
Connecting all Negatives (Black wires)
Connecting All Positives(red wire)
Step 8- Connecting - DC 12V Male - Female Connectors
Connecting the DC 12V Female Connector to the circuit...check the color marking on the connector wire. One needs to be careful with that. Red shld be connected to positive end of the circuit which in this case is also red.
Similarly connect the male connector to the DC Adapter output wires. Single mismatch will case the circuit not work, however, double mismatch will work


Connecting Male connector to the Adapter output wires- Note the white marking on the connector wire...same/similar color marking on the Female connector too, so that the wires are connected in sync...
The Male connector(left) and the female connector (right)
And when its connected-
Step 9- Adding the Leds on the star bases.
Add some thermal Paste at the center of the bases like shown in the below pic
After that solder the leds to the bases. +ve end of the leds should be soldered to the '+' marked areas and negatives to the '-' marked ones.
How to chk led terminals- get two 1.5v batteries and get a battery case for 5-6bucks for the selected battery model, connect the case's terminals to the led's terminals and chk which is what terminal. you will know when the led lits up...

Step 10- Testing
As Every set is in parallel, even if any set goes dead due to some reason, rest of the sets will still work. like the below one-
After connecting and making the connections work, i put on top of one of my tanks and it looked like this...However, plz dont judge the brightness with a camera pic......so try it out urself and chk how this work out

Thanks a lot to @xarg0n and @souvikray for the initial push to get me started along with their practical experiences on building these and finding raw materials... Thanks dadas


Please feel free to ask any questions in case of any doubts and also correct me in case if u find some issues in my understanding. I will be greatly thankful.