[Hoppy]

One possibility is to use a 10 inch square aluminum plate as a heat sink, and attach 9-10 strips of SMD5630 LEDs side by side to the face. With that right on top of the tank you should get good low-medium to medium light intensity. I would use one or two strips of green and red SMD5050 LEDs mixed in, to get better color rendition, with the others all cool white. See http://www.plantedtank.net/forums/showthread.php?t=545113&highlight=smd+5630 for my results doing that. It is a pretty easy project.

 

[thumper_65590]

thanks Hoppy. How thick should the aluminum plate be?

 

[Hoppy]

The aluminum plate needs to be just thick enough to hold its shape easily, perhaps a 16th of an inch would do it. The LEDs don't waste a lot of heat, just enough to justify using the heatsink. But, be aware of the glare that LEDs produce unless some kind of shade is used to block the view of them. If this sits right at the top of the tank even an inch skirt around the square would be sufficient.

 

[thumper_65590]

Hoppy, another question concerning those lights. All I could find them in was a 15 ft roll. Can they be cut down, etc? I can get the aluminum without a problem, and i was planning on having the glass top over the tank, and then a hood. I have a fan I can put in it to get rid of some of the heat, so that won't be a problem either, especially since I am building my own hood, and with the glass it should hopefully cut down on the moisture the lights are exposed to. THe other question is, what type of controller do I use for these. Thanks again for the help.

 

[Hoppy]

You can buy the SMD 5630 tapes in 5 meter rolls, or, sometimes in 50 cm lengths (20 inches) They consist of individual LEDs wired in parallel (usually in groups of 3 of them in series, with those groups wired in parallel) with a current limiting resistor (ballast resistor) in series with each LED or group of 3 LEDs. You apply 12 volts to the leads, and the current will be the design current for them. To dim them you reduce the voltage a bit, and to brighten them you increase the voltage a bit (not a good idea). No controller is needed, just a 12VDC power supply with adequate current capacity to handle the length of tape you have wired up.

If you use 10 rows, each 10 inches long, that is about 2.5 meters, so one roll of LEDs is all you need. But, to add the colored LEDs you have to buy them separately, and those can be obtained in 20 inch lengths. All of this type of LED tape comes either waterproof, or not waterproof. If you have them right at the top of the tank, they should be the waterproof type.

 

[thumper_65590]

could I put a rheostat on these to control the brightness of them, or would I need a different way of dimming them and ramping up the moonlights? I would like to have a gradual transition from daytime to nighttime viewing.

 

[Hoppy]

The SMD LED tapes are not a good fit with a programable lighting scheme. For that you would do far better to use individual LEDs, probably star mounted.

You could work out a way to adjust the brightness with a potentiometer when using the LED tapes, but it would be a clunky system, in my opinion. And, you can buy some SMD tapes, with remote controllers so the brightness and color are variable, but that is something I have done no experimenting with, even though I have a couple of the simple controllers to play with.

 

[skanderson]

I would use a 30 watt bridgelux bxra in 5k or 4k or better yet a luxeon cob in 5k with a cri of 80 or 90. if you get one that puts out over somewhere around 1500 lumens you would should have enough light. 60 degree optics and mounted on a 6 inch makers heatsink. you could add a couple red or blue leds if you wanted to tweak the spectrum for pop.