LED Floodlight For Planted Tank

Using 20W LED floodlight for my 1ft tank. It is very easy to do, everyone should be able to DIY, just need to extent the wire to the wall socket. On second thought, I should not classify it as DIY :p

PAR reading for various light on the same tank:
20W LED 15cm from water surface.
- 1cm above water: ~201 umol
- water surface: ~169 umol (sensor fully submerge)
- 20cm below water: ~66 umol

6.5W LED WEIPRO 7cm from water surface.(120 small LED inside)
- 1cm above water: ~67 umol
- water surface: ~55 umol (sensor fully submerge)
- 20cm below water: ~18 umol

55W PL Aquasonic Fluorescent 7cm from water surface.
- 1cm above water: ~267 umol
- water surface: ~244 umol (sensor fully submerge)
- 20cm below water: ~76 umol

Comparing all 3 lights, WEIPRO 6.5W LED is pretty much useless for planted tank. I surprise ho fast the PAR reading drop on the Fluorescent light, at the bottom surface it is pretty much same intensity as 20W LED. It is not practical but just for curiosity, I measure 7cm under 20W LED and PAR reading was 558umol.

You can also do something like below which my friend did on his 3ft tank

Making Stand for my 2ft LED

Simple DIY stand for my 2ft DIY LED light set.

The materials are all from Daiso ($2 shop)

Cut into couple of pieces

Cut small hole to sit on the glass edge

Nail it together, top view

Side view

Place it on top of the tank

DIY LED Set for 2ft tank (2nd gen) result

Some close up picture of my 60cm tank using 12x3W CREE XR-E Q5 LED. Very satisfy with the result. I can easily grow pink tip and creeping Rotala sp goias.

DIY LED light set for ADA mini S

Another DIY LED light for my ADA cube garden mini S tank.

Material:
1. 62x5cm aluminum plate, used as a heat sink (US$10)
2. CREE XR-E Q5 LED (US$3.95x3 = US$11.85)
spec:
- 3.7V typical driving voltage
- Manufacturer Rated 228 Lumens at 1000mA input current:350mA: 107~114lm
700mA: 171.2~182.4lm
1000mA: 214 ~ 228lm
3. 900mA 10W Constant Curent Source LED (US$5.61)
Driverspec:
- 10 watt high power LED driver

- Input voltage: AC 85~265V

- Output voltage: DC 9~11V
- Output current: 900mA4.
Miscelaneous items: thermal paste, screw and bolt, cable and small container

Top view of the vertical stand. The screw hole is used to adjust the LED height.

Side view

Top view of the horisontal part, this is where the LED be. I will be using 3x3W CREE XR-E Q5 LED.

Side view

Combine both vertical and horisontal.

Electrical wiring

Light set hand on the cube garden. The height of the LED is adjustable. Below photo is where it set to maximum height.

DIY LED Set for 2ft tank (2nd gen)

From the previous design which is 6x3W LED for 2ft tank, I found that it is not bright enough. For this second generation I add another 6 LED, thus total 12x3W led. Still 2 rows but 6 LED for each row.
This time I drive both row together using off the self constant current source LED driver
LED driver manufacturing spec:
- Input voltage: AC 85-265V
- Output voltage: DC 28-45V
- Output current: 670mA

The result is quite good, brighter than 2x36W PL light, more LED mean brightness more uniform and all the plant produce bubble 30 minutes after light on. I do not have equipment to measure brightness nor PAR, so I wonder if I put too much light but never mind, will see how it goes.

Initially I was worry about the heat generated by LED. In the previous design there are only 3 LED on the 5x60 cm aluminum plate, now its double and it is not a heat sink just a plate without fins. Temperature measured just right under the LED heat sink show maximum 49.7 degree C. Not sure the Juction temperature though.

My guess probably because the LED driven at 670mA instead of 1A. I did current measurement using Tektronix current Probe and LeCroy scope, it show that maximum current is ~897mA, minimum current is ~589mA and average around ~720mA. Voltage measured at the driver output is 36.75V. Thus the LED took around 26W.

Power used by the whole light set (LED + Driver) is around 27W. LED alone take 26W, thus LED driver efficiency is not that bad, only 1W power loss.

DIY LED Set for 2ft tank

It has been a while for me wanted to try LED light but it always been turn off due to the price as well as the fact that not all LED light set in the market can grow plant. Most of them just bright enough for us to see but not for plant to grow. It may not designed for planted tank. The one that design for planted tank cost very-very expensive. So I decided to DIY my self.

My target is to replace my 2x55W PL light set with LED. I choose to use CREE 3W led because I read from forum and some people said that those small LED does not have enough PAR. This project total cost is about S$30 for each row, my plan to make 2 rows for better coverage.

By the way, I found this light calculator to calculate PAR for different type of light. http://www.defblog.se/LightCalculator/

Material:
1. Two 62x5cm aluminum plate, used as a heat sink
2. CREE XR-E Q5 LED x6
spec:
- 3.7V typical driving voltage
- Manufacturer Rated 228 Lumens at 1000mA input current:
350mA: 107~114lm
700mA: 171.2~182.4lm
1000mA: 214 ~ 228lm
3. Two 900mA 10W Constant Curent Source LED Driver
spec:
- 10 watt high power LED driver
- Input voltage: AC 85~265V
- Output voltage: DC 9~11V
- Output current: 900mA
4. Miscelaneous items: thermal paste, screw and bolt, cable and small container

Drill some holes on the Aluminum plate to mount the LED

Drill some holes also on both edge. This is more for safety, to prevent the module from droping into the fish tank

Drill holes for LED mounting
LED is screwed to the aluminium plate
Finished module