Your input on my idea to make a led system

[Corvette Reefer]

http://i839.photobucket.com/albums/zz316/jordan_arnett/LEDsetup.png

okay i got a 20 gallon high tank and this is my idea to build a led system. the black would be the heat sink then the color would be the leds and what color they will be and the gray is what i will mount the heat sink to. i would use Cree XR-E bulbs for all them but the reds, the red would be Cree XR-C, id use a BuckPuck 700mA dimming, and a 12V power supply. what do u think of my plan, any recommendations or changes i should do? Also i was woundering what would i mount the heat sinks to for the fixture its self to put on the tank and how do u mount the sink to what ever u want for the cover of the fixture? thanks for the help!

[evilc66]

I would avoid the red LEDs in all honesty. They are very bright (your eyes are very sensitive to it), and will be very distracting. If you want to add a little more red to bring out certain colors in the tank, then use neutral white LEDs opposed to cool white. They aren't as bright, but they help with certain colors.

As for the rest of the layout, I'd add a few more LEDs to just make the output a little more even across the tank. Make 3 groups of 4 LEDs, if you want to keep the layout you have now. Each group would consist of 2 white and 2 blue LEDs. Starting with an even ratio will get you in a 14K temperature range. If you use dimmable drivers, you will be able to adjust from that point, higher or lower. If you are going to use Buckpucks, get two total (one for blue and one for white), and run it off a 24v power supply. MPJA has a good, inexpensive unit from Potrans (24v, 6.5A, $15). Smaller heatsink will work, but will be dependant on a fan for temperature control. If you want to improve things thermally, but still keep it cheap, use a sheet of aluminum to mount everything to. Sandwich the sheet between the LEDs and the heatsink. It will create a much larger area to mount the LEDs to (most small PC heatsinks don't have a huge mounting area), and add more mass and surface area for cooling.

[Corvette Reefer]

okay thanks! so like this?
http://i839.photobucket.com/albums/zz316/jordan_arnett/LEDsetup2.png

what is a good website to find all this stuff for cheap? i found this one and it looks good ledsupply.com anywhere u can find these LEDs for about $5 a piece... also when u get a buckpuck dimmable driver do u have to get a special controll to dim them or is it built into it?

[Corvette Reefer]

Also would there be a difference between using Cree XR-E Star and Cree XR-E Emitter? I origanly was gona get the start but the emitter is about $2 cheaper.

Also how do u think this would work on my size tank? http://www.fosterandsmithaquatics.com/product/prod_display.cfm?c=3578+3733+10704+21973&pcatid=21973

[evilc66]

Stars make life a lot easier for mounting and soldering. Unless you know what you are doing, avoid bare emmiters.

For a good price on LEDs, we (Nanocustoms, we are a sponsor here) sell LEDs and accessories. We don't sell the Luxdrive Buckpuck though, and don't have a simple option for a dimmable driver for 6 LEDs. If you wanted to forgo the color temperature adjustment option, the Meanwell ELN-60-48D will work, and you just put all 12 LEDs on a single driver.

[Corvette Reefer]

i definably want a dimmable driver, but do i need a separate controller or something along with the dimmable driver? or is it built into the buckpuck?

[evilc66]

The version you want is the 3023-D-E-1000. That's 1000mA, externally dimmable. If it doesn't come with a pot (depends where you buy it from), you will need a 5K ohm linear taper pot (easy to find at Radioshack). Buckpucks can be used with a reef controller, but with a little modification. You can't hook them directly up to one.

[fawkes]

Evil has indicated that the red LED's are distracting. Does anyone know about research that tested color needs of corals? Leaves on plants use red and blue and reflect green (that is why we see them as green)..

[evilc66]

Photosynthetic corals use the same chlorophyll A and B as plants, but have more of an emphasis on blue light, around 450-460nm. White LEDs produce a good amount of blue, but just enough red to satify that end of the chlorophyll's needs. The royal blues at 455nm sits really close to the blue response peak for both chlorophyll A and B. That's the basics for growth potential, but certain color rendering issues are still being sorted out.

[fawkes]

Thanks, Evil. It is useful to know. I assumed that there was red in the white LED's. I would think that somewhere someone is trying red/blue to see if they can maximize growth. But if you have to add white to see the stuff, it does make a compelling case for not using just red/blue.

I grow (too many) orchids. Just this week, I ordered a couple of panels of red/blue LED's to try on a smaller growing area. Many of the folks using LED's for plants are not using white - or less of it. It will be interesting to see if there is any change in growth and flowering. If this works I will trade out the 800W MH/HPS combination lamp in the larger growing area. It will probably cut my lighting expenses by more than half. But it will probably mean that I will have to use the ceiling lamps when I am working on the plants...

[evilc66]

I have never been a big fan of using just blue and red for growth. I always feel there is something missing. Granted, in theory it's the most efficient use of light, but doesn't always yield the best results. I'm a much bigger fan of using a broad spectrum light for marine and terrestrial growth.

[fawkes]

You may well be right. That is why I am testing and not committing the entire collection to the test. I may hate it. If it goes bad, I will have some parts to use for some DIY project :)

Many years ago, a bonsai grower insisted that his mix for his trees had to have some dirt in it. He just couldn't bring himself to not use it. I have seen trees growing very well in soil-less mixes. And certainly hydroponics shows us that soil can be avoided. That said, all that is avoided is the soil - they still add the nutrients.

[Corvette Reefer]

k thanks, do u have a diagram on how to wire up everything?

[Corvette Reefer]

do u have a diagram to show how u wire everything up, im kinda confused on the wiring.

[Corvette Reefer]

oh and if i want the ability to put a power switch would i want 2 12 volt power supply's rather than just 1, so each color can have independence? also how do u chose how many A's i need 2.5, 4, 1.7, what ever how do i know?

[evilc66]

Wiring is pretty straight forward. The Buckpuck shows it fairly clearly. Just duplicate for each color. If you want to be able to turn each color on and off seperately, at least by timers, then you will need two power supplies. One for each color. If you just want to turn them off manually with a switch, then you can use just one power supply, and a switch inline with each Buckpuck. As for capacity, just get something a little larger than you need for the load. For example, if you run one 1000mA Buckpuck on one power supply, then you need about 1.2A or greater. Whichever way you go, you will need it to be 24v. That is mandatory.

[Corvette Reefer]

alright thanks i got 2 swiches already i can use so i guess just one power supply, okayyyy i got it thanks for the help.

[Corvette Reefer]

http://ledsupply.com/aata-5g.php
can u use this stuff to mount the heat sinks and leds and aluminum sheet together?

also how much power will these have over t-5 or halides, for the set up im got in mind?

[Corvette Reefer]

do i need 24V for each driver or together? i calcualted that with 12V to one driver with 6 bulbs each bulb gets only 2V, with 24V it gets 4V. and they say the bulbs handle 3.3V, soo idk.

[evilc66]

http://ledsupply.com/aata-5g.php
can u use this stuff to mount the heat sinks and leds and aluminum sheet together?

also how much power will these have over t-5 or halides, for the set up im got in mind?

Yes, you can use that. It's pretty permanent, and needs pressure applied to the LED as it cures to get the best performance.

As for power, you should be similar to a 150W MH.


do i need 24V for each driver or together? i calcualted that with 12V to one driver with 6 bulbs each bulb gets only 2V, with 24V it gets 4V. and they say the bulbs handle 3.3V, soo idk.

Doesn't work that way. LED drivers will automatically adjust the voltage to the needs of the LEDs. With a buck type driver like the Buckpuck, you need to have the input voltage higher than the forward voltage of the LEDs. If you were to run 6 LEDs with a 12v power supply, you would kill the driver in seconds. For 6 LEDs, you need at least a 24v power supply.

You don't need a separate power supply per driver, but it offers more control. You can run more than one driver per power supply as long as it has enough current to handle the number of drivers. You add the max current for each driver together, then add a little for saftey, and that's the minimum current you need on your power supply. For example, two 1000mA drivers would need 2.2A or more.

[Corvette Reefer]

ohhhhh okayyy i see so just get one 24V 2.2A or higher power supply to run both drivers together, and ill still be able to turn each driver on and off right with a switch right??

[evilc66]

If you only want to manually turn the drivers on and off, then yes. Two switches placed between the power supply and the drivers will work. NEVER EVER place the switches between the driver and the LEDs.

[Corvette Reefer]

on the manual they say place it between the CTRL and REF

[evilc66]

Same difference. It's either kill the dimmer signal, or kill power completely. Same end result.

[Corvette Reefer]

If i do 2 drivers i need 2 12V 1.2A, for each one? or 24V 1.2A for each one?

[evilc66]

You double the current, not the voltage when wiring drivers in parallel to the power supply. The voltage of the power supply will limit the number of LEDs you can run in a single series string. The current rating of the power supply will limit the drive current of the driver you want to use, and the number of drivers you can wire in parallel.

[Corvette Reefer]

So the voltage u must divided up between the total leds on a series, and you need the current for the power and if the you want 1000ma led power to each one, you only need it for the driver wich then the driver gives each led 1000ma but you dont need like 6000ma for 6 leds but two drivers make 2 differnt serioes so each driver has to split the current from the power supply from 2000m to 1000ma to each driver? thats how im understanding, is that correct?

[evilc66]

Well, that was painful to read, but I think you have it right. Just to clarify though:

Some basic electrical rules:

Devices wired in series - voltage adds, current is the same at all points.

Devices wired in parallel - current adds, voltage is the same across each parallel device.


So, your source voltage (the power supply) has to be greater than the total forward voltage of all LEDs connected in series. This is especially important with DC buck drivers like the Buckpuck, as they need a few volts above the forward voltage of the LEDs to operate properly. The source voltage still has to be within the limits of the driver though. AC drivers like the Meanwell and TRP drivers already have that taken into account, so you just have to stay within the voltage range of the driver.

All constant current LED drivers will adjust the output voltage to match the needs of the LEDs connected to it, regardless of if the input voltage is much greater. You can run one LED on a Buckpuck with a 24v supply, and everything will work just fine. What you can't do is run 6 LEDs on a 6v power supply. You would need a boost driver for that (boost steps voltage up, buck steps voltage down).

If you are wiring LEDs in parallel to a single driver (not recommended), both parallel strings have to have the same number of LEDs, and preferably the same forward voltage. If you are wiring drivers in parallel to the same power supply, the power supply should be rated for more than the drivers are rated for. If you want to run two 1000mA Buckpucks, you should be looking for a power supply with more than 2A capacity. The reason you do this is so the power supply is not running at it's limit all the time, which reduces heat, and extends life. The same should be done with even a single driver on a single power supply.

Make sense?