I got my LED's in a group buy, 36 whites, and 3 dimmable drivers, about 220 in LED and drivers and then about 60 in aluminium to make the heatsink/array

I figure about 600 by the time I get my blues.

oh really 36 whites and 220 leds of blue

you got your stuff from nanotuners

36 whites and 3 drivers for $220.
Don't have the blues yet.


LEDsupply.com

Here's what I would suggest:

1. 50:50 mix of cool white and royal blue LEDs is good. Mixing regular blues or other colours in there probably doesn't really make a huge difference. Red emitters look ugly and I have experimented with greens and violet and they look interesting on their own but don't add much when used with the white and royal blue.

2. For a 24" deep tank and seeing as you are replacing 400W MH you will likely want to use 40 degree optics to achieve similar PAR at the bottom of the tank. That means using more LEDs. You asked about a 48" array which will only work if you have little on the ends of your tank? How is your rock etc. set up? Do you have clams and SPS all the way out to the ends?

If you want good PAR coverage over the whole tank you will need to go closer to the ends. Generally you want to space your rows front to back 3 inches apart and you can leave 4" or so from the end of the array to the glass. In each row with 40 degree optics it would be best to space LEDs 1.5" apart but you could go up to 2". 2" might cause a bit of spotlighting in the first couple inches of the tank depending on the height of the fixture.

So if it were me I would try to do 6 rows of LEDs (you might get away with 5 rows if you have more open space in the front or back of the tank). Each row would have 36 LEDs spaced 1.5" apart. That works out to 216 LEDs and along with drivers that will be pricey. But to give similar performance to 400W halides there is no cheap solution.

3. Look at the Meanwell drivers. They are more reliable then buckpucks which tend to burn out if they overheat. They also run right off 110V AC rather then having to have a bunch of 24V DC adapters for the buckpucks. So for 216 LEDs you are probably looking at 18 Meanwell drivers.

HTH to start.

Holy heck ron thanks alot the 400 w that isnt a problem sinceI use to have 250's over my tank the tank, houses Aussie Acans & LPS and 3 clams squamosa 10", 8" 5".

what is the average price of LEd's the cool white and Royal blue ron , is thee another place that you can get them from other then led supply.

Couple things.
50/50 split you will get very white light. I much prefer the bluer look like 20000k MH. So 2 blues to every white. Also keep in mind the whites are brighter then the blues to start with.
Get dimmable drivers (only a couple bucks more) so you can have more control.


I have to disagree with your optics recommendation.
see this thread,
http://www.reefcentral.com/forums/sh...ght=led+optics
70 degree optics provided the best results.


I do agree the meanweel drivers are the best buy.

Ahhh, I looked at things again and I thought you wanted high PAR for SPS. In that case you could use 60 degree optics and fewer LEDs space 2.25 inches apart. That would give you 25 LEDs per row if my math is right? That sounds about right as I used 20 LEDs for 4 feet with this configuration and you are one foot longer.

LEDs run USD $5 to $6 each mounted on stars. You could try nanotuners.com and see if they can give you a good deal on LEDs, drivers, optics etc as a large package deal? Some people really like Cutter Electronics in Australia or also ETG Tech in the US for larger buys.


But if you run dimming drivers you can then fine tune the colour temperature to exactly where you want it. 2 blues to 1 white will not give you the option to go more white if you want to.

That reefcentral article is okay but the problem is that he simply changed optics and did not adjust LED spacing. The two have to go hand in hand. If you go narrower optics for greater penetration of light into deeper tanks you need to space the LEDs closer together to get additive PAR. His results are not surprising given the way he did it. The conclusion is that for the spacing of LEDs he used 70 degree optics are best at the particular distance he measure PAR. If he had spaced the LEDs closer together and used tighter optics he would have likely seen higher PAR. This was not a scientific study that can generally be applied to all LED setups, only to those particular strips he used at the depth he measured.

So Ron you have 20 LEd's for each row of 48" right and how many rows did you do my tank is 24 wide.

I have 4 rows for my 18" wide tank. So ideally you would want 6 rows. But since you a doing LPS etc. rather then SPS as I have you may get away with 5 rows. If you want the ability to have higher PAR for SPS in the future then go 6 rows.