How many moonlight led's should I use on my 40High?

[sco999]

I am in the process of finishing my canopy for my 40High reef tank. Tank dimensions are 36"x12.5"x18". How many moonlight led's should I use? I have 10 of them but I am afraid if I use all 10 it will be too much light for the critters. Here are the specs for the LED's I will be using: 4000 mcd, 465nm wavelength, 5mm dia meter, 30 degree LEDs. So the questions are, how many should I use, how far apart should they be, and how far off the water surface should they be?
Thanks

 

[shoimen]

I don't beleive there are actual specifications that are required for moonlights. They are more of a decorative feature in my opinion. I would suggest 3-4 for a tank that size. But this all depends on what you like. Just dont make it too bright for the fish.

 

[robchuck]

10 would be too many. The 3-4 recommendation made by shoimen seems reasonable. I had 2 LEDs over my 29g and 4 LEDs over my 65g when those tanks were set up and was happy with the amount of light.
I've always had them mounted about 6-8" above the water, but aimed into a reflector. The ripples from the point source of the LEDs aren't as prounounced this way, but the tank has a more realistic moonlit appearance this way (in my opinion at least).

 

[sco999]

If I aim them into a reflector, should they be mounted hoizontally similar to the way a MH bulb sits in a retro kit. If I do this I might be blocking some of the light from my MH since the reflector on the MH takes up the entire 12" depth of my tank. Any suggestions on where I should place them?
Thanks

 

[pyro]

I would think the opposite. I would mount them pointing into the reflector. Metal Halides put off light in all directions, LED's only put it off in the top 30° of the lightbulb tip.
That is my thought, but it is out on a limb, so make sure you get others opinions first - I am going to start this project as soon as I finish my auto-top off system I've been working on.